Gabriel says Arsenal must stay calm after their shock Champions League defeat to Olympiacos.

The Gunners had won their previous two matches - at Tottenham Hotspur and Leicester City - before Tuesday night’s game at Emirates Stadium.

Arsene Wenger’s side host Manchester United on Sunday, and Gabriel says that the team must remain confident ahead of the match.

"We only have ourselves to blame for conceding them and now we have to rest, work harder, and then on Sunday come back and have a good game" Gabriel

“It was a complicated night [against Olympiacos],” he said. “We were in a good place in the first half, defending well, we were happy. But the three goals were our own fault.

“We only have ourselves to blame for conceding them and now we have to rest, work harder, and then on Sunday come back and have a good game.

“We just need to be calm. We have to work hard and focus on putting in a good performance [against Manchester United].

“I am sad that we lost an important game at home. But we can still qualify. We have a very strong team, with some very good players. We now have to try to win the remaining matches in the group.”