Arsenal boss Unai Emery felt Ainsley Maitland-Niles' red card was the difference for defeat to Leicester City.
The Gunners played for an hour with ten men as Jamie Vardy (2) and Youri Tielemans struck for the Foxes.
Emery said: "We worked, we prepared our game plan, 11 v 11 the match was going like we prepared.
"For me the first yellow card for [Maitland-Niles] is not for me, it has affected our game plan a lot. One player less is difficult.
"Today the condition [for losing] is the red card.
"We will continue, we will not look at the table, the Europa League is a big motivation for us to win it."