Lacazette was shown a straight red for elbowing Aleksandar Filipovic as Arsenal suffered a 1-0 loss away to BATE in their last-32 first leg.
The forward was given a three-game ban and missed Arsenal's comeback in the second leg, as well as their 3-1 defeat away to Rennes in the first meeting of their last-16 tie.
But UEFA confirmed on Tuesday that the suspension has been reduced to two matches and, as he has already sat out two games, he can play against Rennes at Emirates Stadium.
Unai Emery had said of Lacazette's dismissal at the time: "I didn't see the action but we spoke and frustration needs controlling. It's bad news with the red card."
The France international has hit 14 goals in all competitions for Arsenal this term, having formed a dangerous partnership with Pierre-Emerick Aubameyang.
Emery has been urged to keep his front two in tandem, with Martin Keown calling on the Gunners to stick with an attacking XI.
He has said in the Daily Mail: “On Sunday [against Manchester United], Emery's team showed all the ingredients necessary to finish in the top four. If they are to do so, the manager must resist the urge to tinker.
“This team have struggled to find a way to be successful on the road. Emery has made 76 changes to his starting line-up, the third most of any manager in the Premier League this season.
“When Arsenal were winning titles, they did not have one team for Highbury and another for away games. It was the same XI every week.
“It is time for Emery to trust the players who battled so valiantly to beat United to see Arsenal over the line.”