Arsenal boss Arsene Wenger admits he may have to carefully monitor the fitness of in-form striker Alexis Sanchez.
The Chile international, who joined from Barcelona for £35million in the summer, has already made 22 appearances for the Gunners in what has been a sizzling start to his career in north London.
Sanchez has been influential for Arsenal by scoring 14 goals but his hard-working play may have to be observed closely over the hectic Christmas schedule according to Wenger.
"When you have a player who wants to run, you don't stop him. He is enthusiastic, he loves to play. He has quality that in the morning he comes in and he is fresh - I don't know what he does overnight," said Wenger ahead of Saturday's trip to Stoke City.
"You can see that when he plays but he can dig deep. He played his 27th game on Wednesday since the start of the season, if you consider international games - and travelling [back and fore to South America] on top of that.
"He is in the red zone.
"Unfortunately you never know how far you can push (a player). We are not scientific enough to predict that completely, but he has a great recovery potential.
"He recovers very quickly, is always sharp and wants to play.
"Alexis has a huge desire, no complex, and has a fighting attitude that means even when he misses something it doesn't affect him.
"He is very mobile, very determined and he has the sense to be in the right place in the box."
