Look who's back! Gallas in Champions League
Arsenal top Group G with eight points and victory over Dynamo Kiev at the Emirates will see them safely through, although their form of late has been poor.
French central defender Gallas was stripped of the captaincy and dropped for the 3-0 defeat at Manchester City on Saturday after comments about team mates in the media.
"I think (Gallas) could be stronger as a player now because previously he took all the problems of the team to his heart," Arsenal manager Arsene Wenger, who has made Cesc Fabregas club captain, said on Monday.
Manchester United and Villarreal meet in Spain in Group E with a draw enough to put both sides through.
Real Madrid can afford no slip-ups in Group H when they face BATE Borisov. With Juventus already through, the second-placed Spaniards will join them if they win in Belarus although a shock defeat would leave them sweating.