The Chile international came off the bench to feature in their first match of the season, a 0-2 defeat to West Ham, and could play more of a part against Crystal Palace this weekend. This is despite helping his country to win the Copa America over the summer, and suffering a dip in form towards the end of last season.
However, his manager believes that the former Barcelona man needs this intensity to be happy. The player has also been training by himself, meaning that he could well be more ready for regular football than expected.
“I am a bit worried about him coming back too quickly,” said Wenger, “But on the other hand I knew before the start that once he is here, he would be difficult to stop. He practised for two weeks before he came back — he did not start from zero. He works extremely hard in every single training session to show that he is ready.
“What he does is, for me, normal. It is what everybody should do. You wonder if he has created a beach at home, and runs along the living room. He is a hyperactive guy. He needs that to be happy.”
He added: “He is very ambitious. He wants to win. He knows he won the FA Cup, the Community Shield, he wants now to look to get more. And he is a winner. This season, he knows what is expected from him, and he will do better than last year.
“He made 52 or 53 appearances last season — plus the Copa America. In March, April, May, you could see he was a bit jaded. But he is still a guy who can make a decision in a game. And once he is out there he gives 100 per cent.”
The North London outfit have been tipped to challenge for the Premier League title during this campaign, and the 26-year-old will have to be on top form if they are going to do so. He scored 25 goals in 52 appearances during last time round, and will be looking to improve on that after having a year to settle in.