But Sharks boss Philippe Saint-Andre has talked up both players' fitness prospects for a crunch Edgeley Park encounter with European champions Munster on Sunday week.
Full-back Tait (sore hamstring) and prop Sheridan (arm) both miss the opening Pool One appointment with Saint-Andre's former club Clermont Auvergne at Parc des Sports Marcel Michelin.
Scotland international Rory Lamont wears the number 15 jersey, with Frenchman Lionel Faure packing down in Sale's front-row alongside Neil Briggs and Eifion Roberts.
But former England fly-half Charlie Hodgson has been relegated to bench duty as Saint-Andre hands Richard Wigglesworth - England's RBS 6 Nations scrum-half last season - the number 10 shirt.
Saint-Andre said: "It has been a difficult week preparing for the game with Mathew Tait pulling out with a sore hamstring.
"But both he and Andrew Sheridan should be fit to return for the Munster game.
"Games don't come any tougher than this one on Saturday.
"Clermont topped the table (France's Top 14) last year, and they have started well this season. They will attack from the start, and we need to be ready for them."
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