Arsenal manager Arsene Wenger insists Granit Xhaka is not a dirty player despite the midfielder's indifferent start to life in England.
The 24-year-old arrived at Arsenal from Borussia Monchengladbach in the off-season with a reputation as a rough player.
Xhaka has been sent off in the Premier League and he gave away his latest penalty in a 3-3 draw against Bournemouth last time out.
But Wenger believes the Switzerland international is showing improvement defensively, denying claims he is dirty.
"You can see in his game he is not a dirty player. Overall I am quite happy with his defensive evolution," the Frenchman said.
"He is less spectacular in his tackling and he stays more on his feet. He uses his body better to win the challenges and his recovery runs are stronger when the ball goes behind him.
"He is much more focused defensively than before. He has improved a lot on that front."
Wenger needs Xhaka at his best, particularly with Santi Cazorla still sidelined and Francis Coquelin set to miss four weeks with a hamstring injury.
As his team prepare to face Preston North End in the FA Cup on Saturday, Wenger also said he feels Xhaka has been unlucky with the spot-kicks he has conceded.
"He has conceded a few and I agree he has to stop that," he said.
"But always it's... is it really a penalty or not? I think he was unlucky on both occasions, but he has to adapt."