Arsenal manager Unai Emery is very pleased with the impact of summer signing David Luiz.

The Brazilian central defender arrived from Chelsea and has helped Emery tighten the Gunners' rear guard.

The Spanish boss is also pleased with the influence Luiz has on the squad.

Emery said of his centre-half to reporters: "The most important thing is to have a lot of corners. We had a lot in the first half.

"When we have a lot we can score.

"He is very positive. He is every time speaking about positive things. He is helping the young players.

"He came late in the squad but his commitment is very high, his behaviour."