Despite taking a half-time lead through Jo, City were undone by two goals in as many second-half minutes.
Mancini ended the contest with £100million worth of talent on the pitch, but it was not enough as Boaz Myhill turned away James Milner's last chance at a rescue mission.
The City boss might reflect on his decision to select six youngsters in his starting line-up.
However, with Chelsea due at Eastlands on Saturday lunchtime, Mancini claimed he had no choice.
"I don't regret making the changes," he said.
"I have big problems at the moment and we couldn't take any risks.
"If I had more players available it would be a different team.
"But when you play like us and Chelsea, on Saturday at 12.45, the time to recover is very short.
"They would need minimum three days so to play tonight would have been dangerous."
Mancini added: "Saturday is more important, the FA Cup is more important. The Europa League is more important.
"I did not regard this as a necessary sacrifice. We wanted to win. That is why I had four senior players on the bench.
"But I knew there was a chance we could lose because we started with six young players.
"I am happy with these guys. We might have lost the game but they can improve. If they do not play tonight, when will they ever play?"
Did Mancini make the right call? Have your say.
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Its i fair point he does have to blood the youngsters,carling cup so what....But the same old city fans will be on this very page slating mancini as always!
If we pick up a win on Saturday, then and only then will it be worth it. However, I still can't believe we threw this away because it was by far our best chance to win something, especially with the other major casualties last night.
We need a trophy to shut the rags up and for the benefit of us die hard fans who have spent their lives in the shadow of Stretford Rangers. We are not going to compete with Chelsea to win the league, I'd have rather put some youngsters out on Saturday against Chelsea with a capacity crowd cheering them on.
We needed to win that game last night, it was probably our best chance of silverware.
Yes getting a top 4 place is probably the most important thing but we need to win something!
Yes. He would have been hailed if it came off but i am not bothered. It was a distraction we did not want.
Could not agree with MC more. Compared to 1976 and how football as changed this is a very insignificant trophy. Too many "fans" making comments on other topics are more interested in the 34 year bloody banner at Owed Trafford than what MCFC is trying to achieve. I, like any city fan would like to see us win a trophy but is one more year going to make any difference particularly if it is one of greater significance than the Carling Cup. We are still in 3 competitions and this result is meaningless in regard to the past and future history of our great club.
Before commenting and claiming the end of the world is nigh, just take deep breaths and realise mancini is right. We could have done what Chelsea did and played a few more senior players and picked up 2 more injuries, then that would have been a disaster.
Weve got Chelsea on saturday with a reasonably fit squad still with all to play for.
If we beat chelsea on Saturday this will have been a great decision by mancini.
Believe
Well you should do Bobby Manc - as I have always said, winners dont need a rest and we should have gone to WBA and won the game in the first half and then rested players!!!
This all means nothing if we now dont go and beat Chelsea on Saturday!
how can you have no regrets???? we're not in the cup anymore!!!!!!!
A 350 million pound cowboy outfit!
how can you have no regrets?????? WE'RE NOT IN THE CUP!!!!!!!!
disgraceful Mancini, we want a trophy and we fail at the first hurdle. we have a super squad, no such thing as a weak team. once again people are laughing at us
mancini out!
Mr. Mancini got it badly wrong!!!!
Top 4 is his brief from above. City are looking to the future and the CL and they will take these risks on selection again in the FA Cup.
Sorry Mr Mancini but playing the side that you did showed disrespect to the travelling fans and disrespect to a Cup Competition that in truth, the way the season is shaping up with injuries,was our only chance of gaining any trophy this season.
It also demonstrated the lack of passion in our club as the ream was unable to beat an equally weaked West Brom side.
My total belief in Mancini is now in question after a match may prove to be the start of a slippery slope for our team.
Clearly a win against Chelsea would give renewed encouragement so come on City give us a performance to be proud of after last night's awful result.
I rightly agree with Mancini on this, I mean the squad is 25 and with a big game at the weekend felt changing the side was a good decision. How can these young guys get games if they are not selected, So what we didn't win and went out will Mancini learn from it Yes would be my assumption. One thing that does look good out of this is we have never lost 2 in a row under Mancini so all you tactic and selection haters can have a pop at what I am about to say here.
I would take a win against Chelsea and further our cause in the top of the league than progress into the CC, sorry if that disturbs you somewhat but that is how i feel. We should be concentrating on the Premier league and bettering last season. Ok the League cup is still a trophy but we are never going to do a double are we really. So look at it positively and see that with one cup out of the way means less games, better performances and more focus on the things we should be aiming for.
Instead of whining about it lets just move on and deal with the next task in hand Chelsea.
I dont think anyone can blame Mancini. We've had a shocking time with injuries mostly to defenders with an entire back line out. We've also got a big game on Saturday and next Thursday so he has to protect players. What it does show, however, is that we are still light in a number of areas. It's clear that RSC wants out and with Adebayor throwing his toys out we're left with Tevez and Jo. Need another striker in January and we should try and take advantage of uncertainty at Inter with Milito. Both Johnson (M) and Vieira need to be replaced in the squad to provide more competition. We probably still need another top class central defender as Lescott spends more time injured than playing, Onouha's out on loan and we can't continue to rely on Toure and Kompany. Boateng could play in the middle but then we need a top right back. Disappointing that we missed out but unfortunate with injuries and a hard draw.
I am not interested in what any other supporter thinks, I am only interested in watching the game of football being played well, with spirit and skill and winning something is a bonus.
Watched them virtually since I was born 47 years ago, what is it with the modern mentality of some football fans ( not supporters in my view)!
City are on the up, we know that and we are in a very fortunate position - back the Manager, encourage the team and yes I think its okay to call an over paid footballer who appears not to have the right attitude both on and off the pitch - but please do not play into the hands of a small group of pathetic people - we need stability with a Manager who is both brave and has won something - its been a while coming but coming it is.........
What is being overlooked here is West Brom also put out a second string side and although the result was only 2-1 they battered us for most of the match.Maybe our much heralded youngsters aren't as good as we thought?
I think he made a mistake in his team selection but there again Chelsea and Liverpool did the same and they are out as well.Yet again we exit a cup competition at the first hurdle and for the amount of money invested,injuries or not,it really isn't good enough.
Mancini did exactly the right thing with the options open to him.As you may of noticed many of the other top teams in the Premiership did exactly the same.For some it came off ;for others it didn't.
I'm disappointed live everyone else but believe the real target is to do well in the other competitions.
Incidentely, City fans must have realised by now that what ever we achieve in the future the manutd fans will always be looking to diminish it.It's part of their make-up,otherwise they wouldn't follow that club.
It was a gamble worth taking.
We'll only know whether its paid off Sat afternoon so we should hold judgement until then.
This result will not affect the club's long term prospects one jot.
We have too many short term thinkers in our midst.
Come on blues, beat Chelsea this weekend and things won't seem so bad.
Beggars belief. The Chelsea game is not a cup final. We don't win a trophy if we beat them. IF we win on Saturday - IF - we will still be 4 points behind, 32 league games to play including a visit to their place. Had we won last night we'd have had 6 games between us and a trophy, with the nearest rivals a bunch of second stringers we ate last year and a bunch of gereatrics who struggled to beat the scousers. It's arguable whether the most important game was last night or next Saturday. And we are NOT Chelsea. We haven't won three league titles in the last 6 seasons. Our priority is not the champions league. This club NEEDS a trophy, and last night, Roberto, you threw away a golden chance of having one in the cabinet by the end of February. And you did this by playing a non-squad team. Given got a game behind a back four so young and inexperienced it needed permission to be out so late. Dedryk is very promising but needs either Kolo's or Vinnie's guiding hand to perform at this level. It was almost an insult to a great 'keeper. A three man midfield in front of it and Shay! Jo, Santa Cruz and the exceptonally promising Guidetti up front was OK, but it seemed unlikely they were going to see much of the ball and so it proved. Not only did you lose last night, Roberto, but you lacked respect for the supporters, the opposition and the tournament. Why has the owner spent so much on players and why have you said you'll "keep them happy" with games in the cup competitions, if you're only keeping them a place on the bench in "important" (ie league) matches. Were you REALLY bothered about winning last night? It's highly unlikely that we'll win the premier league, so that leaves the cup competitions. The europa league is the equivalent of half a league season, with so many knock out matches, that slip ups are always a possibility. That leaves the FA cup - which we all want to win. You can't afford another cock up, Roberto.
IN my opinion a shame, but may be a blessing and at least we didn't come out of it with more injuries. It is our least priority so no big deals guys and girls.
Mancini has a real issue with the amount of injuries he has to the first team squad and risking more would have been stupid. The youngsters did ok, but West Brom were the better team and good luck to them.
We are not quite there yet in terms of younger squads like Arsenal and Rags, but this is all good experience and they will learn from this.
All in all, disappointing, but I agree with what Bobby did and it is the least priority out of everything. I think Top 4, Europa Cup, Fa Cup is our priority and another year without a trophy is no big deal....we've gone 34 years without so far and I would have top 4 and Champions league over a trophy this season.
Now lets have Chelsea on Sat and make all happy again!
CTID
Why are we so obsessed with what the Rags or anyone else says. I am as disappointed as anyone with the result but we have a big injury list that risked growing bigger. How many of the fans bewailing this defeat would be happy if we won the Carling Cup but did not achieve any of the larger goals. Of course if we don't achieve any of them ... that is another story. It is all too easy to come out with the mantra Mancini out! but they singularly fail to name a better alternative. O'Neill? No thaniks, no plan B poor record in the transfer market - a bit like Roy Hodgson, out of his depth at the very top.
I remember Stuart Pearce doing exactly the same thing but in reverse. Played Wigan at home in the league on the Saturday (and rested players because we had an important FA Cup tie 2 days later) and we lost. Brought back the "rested" players against West Ham at home on the Monday and we lost that one as well. Then we went on a charge and lost 7 out of the next 8 games! Let's hope history isn't about to repeat itself...