Petr Cech felt a toothless attacking display from Arsenal was the reason behind their surprise Europa League defeat at BATE Borisov.
A Stanislav Dragun header on the stroke of half-time was enough for the Belarusian Premier League champions to seal a memorable 1-0 victory over a strong Arsenal side, who had striker Alexandre Lacazette sent off with five minutes remaining
Unai Emery made only two alterations from the team that had beaten Huddersfield on Saturday as Cech replaced Bernd Leno in goal and Granit Xhaka was recalled following a groin injury.
Henrikh Mkhitaryan missed a great chance in the opening 90 seconds before Lacazette headed badly over the crossbar when well-placed.
Cech pinpointed the lack of cutting edge in the Gunners' frontline, which did not include Mesut Ozil after Emery decided to leave the German at home.
"Yesterday it was one of those games where if we played for another couple of hours probably we wouldn't have scored," Cech said.
"But there are games in football like that. You try, you play, the goal does not arrive and you have to go home with the result you don't want but you have to pick yourself up and be ready for the second leg.
"This is the advantage of playing two-legged ties - when one game goes wrong you can always make up for it.
"We didn't take our chances. In the first-half in particular we played well and created enough chances to go ahead in the game but unfortunately we didn't take our chances and then we conceded in the last minute of the first half which obviously gave them a lot of confidence and belief.
"We wanted to score goals and win to put ourselves in a good position. We've left it more tricky for ourselves and we need to win at home."
Lacazette will now be banned for the second leg, which takes place at the Emirates Stadium early on Thursday evening.
Emery insisted after the defeat here that he "trusts" his players to turn the tie around in north London - with Cech echoing the sentiment of his coach.
"We had enough chances to win the game but we didn't," he added.
"We have to make sure we win the home leg and we go through. We have the whole 90 minutes to play for and I am sure we can do that."