Arsenal endured a miserable night in the Europa League as they lost 1-0 to BATE Borisov and had Alexandre Lacazette sent off. Here are the talking points from the game.
Europa campaign in danger
Unai Emery's team selection showed how seriously he is taking the Europa League this season.
The Spaniard, a three-time winner of the competition with Sevilla, used 28 different players during the group stage but he named something close to his strongest side against BATE, Arsenal's first knockout game of the season signalling a change of approach.
Ultimately, however, what looked like a welcome opportunity to lift morale and take a step towards the last 16 of the competition ended in humiliation. This was Arsenal's fifth defeat in 10 games in all competitions, and it could prove to be the costliest. Alexandre Lacazette's late red card capped a miserable evening for them.
It might have been a different story had they taken their early chances - Henrikh Mkhitaryan should have scored in the opening two minutes and there was a bad miss from Lacazette midway through the first half - but BATE's goal arrived on the stroke of half-time and Arsenal created precious little after that.
They dominated possession - the minimum you would expect against such modest opposition - but not for the first time this season, there was a glaring lack of creativity and penetration. Lacazette did have the ball in the net in the 55th minute, but the linesman correctly flagged for offside. Lucas Torreira's wild shot into the stands in the closing stages summed up Arsenal's evening.
BATE defended well in the second half, keeping their shape and their discipline, but the fact they had not played a competitive game for two months made the result even more embarrassing for Arsenal. They have it all to do in the second leg. At the moment, a season that started promisingly looks in danger of ending prematurely.
If ever there was a game to sum up Arsenal's Sead Kolasinac conundrum, this was it.
The 25-year-old was deployed in his favoured left wing-back role as Emery opted for a back three, and as is so often the case, he was Arsenal's most dangerous attacking outlet. Mkhitaryan should have scored from his cut-back after just two minutes, and Lacazette was similarly wasteful from his looping cross around 20 minutes later.
Kolasinac continued in the same vein right up until his 74th-minute substitution. The statistics showed he created a whopping total of seven chances - more than the rest of his team-mates combined despite missing the final quarter of an hour - and he even had a chance to score himself when he fired a diagonal shot wide shortly before his withdrawal.
For all his attacking threat, however, Kolasinac was typically complacent defensively. The Bosnia and Herzegovina international showed little interest in tracking back, meaning he was caught out of position on numerous occasions. Ultimately, all his attacking work was offset by his weak challenge on Stanislav Dragun for what turned out to be the decisive goal.
It presents a conundrum for Emery. Kolasinac is a formidable attacking weapon in a team which lacks spark, but this was further evidence that he cannot be trusted defensively.
Questions for Emery
Emery invited more scrutiny by opting to leave Mesut Ozil at home, but that was not the only decision fans will scratch their heads about. His substitutions did not add anything, with new signing Denis Suarez struggling, and more worrying than that was the absence of an obvious plan.
It is not the first time Emery's side have seemed to lack direction. Their only obvious attacking approach was to release Kolasinac on the overlap, but they once again struggled to create chances from midfield, with Granit Xhaka and Matteo Guendouzi unable to unpick the BATE defence.
They were not the only ones. Alex Iwobi lacked composure at key moments, and it was the same story for Mkhitaryan. It's little wonder that Lacazette's frustration boiled over. The France forward is starved of service in this Arsenal side and it was the same story for Pierre-Emerick Aubameyang, who did not manage a single shot on goal during his 23 minutes on the pitch.
The squad Emery inherited is far from perfect, but Arsenal won 4-2 on the same ground under Arsene Wenger last season with a considerably weaker starting line-up. They will still be favourites to go through when they meet again at the Emirates Stadium next week, but Emery has questions to answer.