The Italian outfit have won only once in their last seven Serie A matches and sit ninth in the table - 22 points behind leaders Juventus. 

However, a win or a draw against Ajax in Group H on Wednesday would see Milan through to the next stage of the competition, and Allegri is confident his charges can avoid a "careless" performance like the one they produced in the 2-2 draw against Livorno on Saturday. 

"I don't have to say much to motivate the players," he said. "I have to sort out two or three small things on a tactical level but I have faith in my players. 

"It's true that our league form isn't the best but we've never let ourselves down in Europe.

"We were a bit careless against Livorno and that's no good, but I don't think we'll have that problem tomorrow (Wednesday). (Stephan) El Shaarawy did good things as it wasn't easy on Saturday. He's in good shape and tomorrow could be his game."

Allegri is hopeful on the fitness of Alessandro Matri and Urby Emanuelson for the clash at San Siro, but Robinho will miss out with a shoulder injury.

"Matri has had a fever for the past two days but he’ll be training with the team today (Tuesday)," Allegri added.

"Emanuelson hasn't been able to get his boots on for the past two days. I hope he'll be available but if not, there's (Kevin) Constant.

"Robinho is out and (Sulley) Muntari is back in. (Giampaolo) Pazzini is making progress while (Ignazio) Abate's still feeling pain in his ankle."