Kevin-Prince Boateng has been ruled out of Schalke's match at Stuttgart, but could return for the crucial Champions League clash at Maribor on Wednesday.
But coach Roberto Di Matteo said he would return more quickly than had been feared, telling a news conference: "He feels a bit better, but that game at Stuttgart is just a bit too early for him. We hope he'll be available on Wednesday."
The Royal Blues need all three points from their trip to Maribor -- and must also hope that Chelsea beat Sporting Lisbon -- if they are to progress into the knockout stages.
But they have lost their last four away games -- at Hoffenheim, Leverkusen, Lisbon and Freiburg -- and Di Matteo said: "We've made it hard for ourselves away from home so far this season.
"We want to pick up points at Stuttgart and hope to begin to show consistency. We want to pick up a good result, and we are working hard to make sure that happens."
Stuttgart are managed by Schalke coaching legend Huub Stevens, and Di Matteo said he had "given them confidence."
Stevens, who won the 1997 UEFA Cup with the Royal Blues, told reporters: "Of course there are still feelings, but you need to shut them out and be professional.
"The past is not that important. Today and tomorrow are more important."