Alexandre Lacazette has apologised for getting sent off in Arsenal's 1-0 defeat to BATE Borisov on Thursday.
Lacazette, who had a goal disallowed for offside early in the second half, was shown a straight red card five minutes before the end of the clash in Belarus when he threw an elbow at Aleksandar Filipovic.
Unai Emery's team must try to overcome the deficit without the France international when they welcome BATE to north London for the return leg next week.
The 27-year-old, scorer of 12 goals in 33 matches for Arsenal this season, took to Twitter after the game to apologise for his dismissal, but remains confident his side can turn the tie around at the Emirates Stadium.
"Letting the team down like that is the worst feeling," he wrote.
Letting the team down like that is the worst feeling..— Alexandre Lacazette (@LacazetteAlex) February 14, 2019
I should have stayed calm but it’s not always easy.. Sorry
There are still 90 minutes to play and I believe that my teammates will make it to the next round.. #COYG #Laca
"I should have stayed calm but it’s not always easy. Sorry.
"There are still 90 minutes to play and I believe that my teammates will make it to the next round."
The latest defeat is Arsenal's fourth in their last seven games in all competitions and was described by club legend Martin Keown as "the worst performance" they have had under Emery since he replaced Arsene Wenger at the helm before the start of the season.
The Premier League side also received a lot of criticism on social media for a performance that saw them land just three shots on target from a total of 16 attempts.