Chelsea goalkeeper Thibaut Courtois hopes to be back in action from a knee injury by December, but the Blues are expected to be without defender Branislav Ivanovic when Barclays Premier League action resumes.
Belgium international Courtois needed surgery following damage to ligaments in his right knee suffered in training last month.
Courtois revealed the procedure had gone well and he was now set to step up his recovery programme.
"In terms of my knee, it is good. I am doing my rehabilitation and it is progressing fine," Courtois said following Belgium's Euro 2016 qualifying win over Israel.
"I will be (now) starting the bulk of the work with my physio to come back as soon as possible.
"Of course I still have to be careful not to go too quickly, but all being well, I should be back in December."
Chelsea have struggled for consistency this season, with the defending Premier League champions 16th in the table, already some 10 points behind leaders Manchester City ahead of this weekend's home clash with Aston Villa.
Full-back Ivanovic suffered a hamstring injury while on international duty with Serbia.
The defender has returned to London to be assessed, with some reports suggesting he could be out for around three weeks, which would see him miss the away Champions League tie at Dynamo Kiev as well as potentially fixtures against West Ham, Stoke and Liverpool.
Chelsea forward Diego Costa will be available again versus Villa having served a retrospective three-match suspension following his altercation with Arsenal defender Laurent Koscielny at Stamford Bridge.
Costa was not involved for Spain during the international break, so used the extra time to help sharpen his fitness.
"It has been really important for me. I have been able to train with my own specific schedule to help me get better and better," Costa said on Chelsea TV.
"The sessions have been good and I have been able to benefit from being here. I have been working on what I needed to work on and I am happy about that."
