A 14 game unbeaten run has seen Peterborough move into fourth place in League One, two places and one point above the Latics.
However, Sheridan is taking heart from Oldham's record of three wins and a draw against the rest of the top six.
He said: "Peterborough are a good team, Darren Ferguson's doing very well and they're probably one of the best attacking teams in the division.
"They have one or two decent players in the forward positions but I'm sure they'll be worried about us as well.
"I think they'll be on a high, they're on a decent run and I am expecting a hard game. If we beat them we go above them and that's what we'll be trying to do."
Sheridan, who watched Peterborough defeat Tranmere Rovers in Tuesday's FA Cup replay, is sweating on the fitness of Sean Gregan and Darren Byfield.
Gregan suffered a mouth injury during Saturday's 1-1 draw against Brighton while Byfield missed the game after suffering a freak toe injury while at home.
Byfield's month-long loan from Doncaster Rovers runs out after this weekend with Sheridan undecided whether to extend it.
He said: "Even though he hasn't scored Darren has been part of the team that's had some good results so I'll have a chat with him.
"He's an excellent player on his day so I'm sure he'll be wanting to prove something to me by scoring."
Peterborough league form: WWWDW
Oldham league form: LWWWD
Key opponent: Craig Mackail-Smith - marksman has been in fine form this season
Prediction: Peterborough 1 Oldham 1 - Latics must be on top of their game but should earn a point
Agree with the prediction? Have your say.
You can get 17/2 on Oldham winning 1-0 with Betfred. For this and more odds, click here.
Tweet
Shaman, Fylde Coast (12/12/2008 at 15:25)