Both went off injured during Saturday's 2-1 win over Hibernian.

But manager Derek McInnes is hopeful they will recover for the meeting of the second- and third-placed sides in the Scottish Premiership.

"Joe's got a nasty gash above his eye," McInnes said. "Sam needs a wee bit of TLC and a lot of things to go his way."

Cosgrove, Aberdeen's top goalscorer with 10 goals in his last 11 games, went off in the 19th minute at Easter Road with a back problem.

"I think it's been the consequence of training on hard pitches with the weather," McInnes said. "We have been indoors a lot and the other night we played on Astroturf at Stenhousemuir, and his back just went into a spasm.

"He felt it a bit on Thursday and hopefully it can be something we can work on and hopefully it can disappear as quickly as it came. He certainly feels positive about Wednesday, but we'll see."

Lewis was injured after colliding with a post while scrambling to reach a Stevie Mallan free-kick, with summer signing Tomas Cerny replacing the Englishman just before half-time to make his Dons debut.

"Joe's absolutely fine," McInnes added. "The medical staff felt he was going to have to get it stitched and it was going to take a long time.

"Obviously it's not ideal, but Joe seems eager to play. I don't think it's anything too sinister."

Aberdeen striker Sam Cosgrove was forced off early with a back injury