Arsenal’s record signing Mesut Ozil needs to develop a more ruthless streak in the penalty area, according to team-mate Per Mertesacker.

The German playmaker netted for the second time in successive games on Sunday as his side overran Aston Villa 5-0 to record their biggest win of the campaign.

Ozil also lit the fuse for Arsenal’s success with an audacious flick-on to set up Olivier Giroud’s opening goal and continue his return to form after a three-month injury absence.

However, Mertesacker – who also played with Ozil at Werder Bremen – believes his former international team-mate would benefit from being more single-minded at times.

“He was always that promising talent, and now he is showing a lot more – he has had so much experience in his young career,” said the Gunners skipper.

“Sometimes I wish he was more selfish in front of the goal, as you can see when he breaks through the lines – he should have scored instead of looking for another player.

“You can see he is dangerous and has pace. When he really wants, he is so quick, and he caused a lot of trouble, and was always a threat.

“It was not on his best position in my opinion – he played more on the left side, but he can play anywhere up front.

“It is good for him to get back his fitness and maybe on the wing he is doing a bit more defensive work as well.

“He suffered a bit at the end of the game, but he always looked dangerous, was always available, wants the ball and wants to create something.”

Arsenal ran riot against their West Midlands visitors, with Theo Walcott, Santi Cazorla – from the penalty spot – and young right-back Hector Bellerin also finding the net.

The result also represented the Gunners’ fourth clean sheet in five games since their 2-0 capitulation at Southampton on New Year’s Day – a match that turned out to be a “wake-up call” for Mertesacker and his defensive colleagues.

“At Southampton, that was a major setback,” Mertesacker recalled. “It was a bad start to the year.

“After that, we promised ourselves to come out of that comfort zone and be a bit more focused, especially that what comes first is defensive work and not just for the back four.

“You can see the benefit when everyone realises that, and I thought everyone realised it very quickly after we lost at Southampton. Maybe sometimes you need a wake-up call in certain times to realise what was really important.

“We worked a lot on our defensive shape, not just the back four, to avoid those dangerous free balls against us. We look much better and the best game defensively was against Man City.

“We talked consistently about how to find our best way, but you have to show it on the pitch, otherwise everybody will doubt you and you cannot see any benefit.”