Chelsea boss Ancelotti admits Drogba desperate for Euro return
He was suspended for the opening two games in the Champions League and missed the win over Spartak in Moscow through a virus.
"He's involved and wants to play," said Ancelotti. "He wants to give his support for the team. He's been out for these games and the team played well and won, but we have more possibilities to win when Drogba is in the team.
"When you have an opportunity to close the game you have to do it. We have a chance to get to the top of the table and play the last group games without pressure.
"Spartak played very well in the last game, above all in the second half. We want to avoid those kind of difficulties tomorrow.
"We had a problem in the second half and played too defensively. We want to play a different game."