Arsene Wenger believes Alexis Sanchez has what it takes to become a World Class number nine as the Chilean international led Arsenal to a 5-1 victory at West Ham by scoring a hat-trick. The French boss revealed that the former Barcelona star struggled with a back problem earlier in the game, but was still able to score three goals in 15 second-half minutes, as the Gunners move second in the Premier League table.

Arsenal signed Lucas Perez from Deportivo la Coruna during the summer transfer window in order to fight with Olivier Giroud for the number nine role. However, Sanchez has established as the first choice ahead of both specialists, following an impressive start to the season, scoring 11 goals in 14 Premier League appearances while providing five assists.

"Look, he has all the ingredients to be a top -class striker and he shows that now in every game. In a game like that today, again he is quick, he is quick to close down, he can dribble, he has short backlift," Wenger said in his press conference after the win over West Ham.

"He has a killer instinct and it shows again that the South Americans, at the moment in world football, are the leading strikers. You have to acknowledge that. If you look through the top strikers in Europe, they are basically all South American now," Wenger said following the win over West Ham.

Yet Wenger revealed that Sanchez's new impressive display against West Ham came despite having some problems in his back during the first half of the game.

"He had a problem in his back at half-time, but he looked sharper in the second half than in the first!" Wenger confirmed when asked whether the Man of The Match was struggling with an injury.

The former Barcelona star suggested during his first years at Arsenal that he liked to play on the left flank rather than on the number nine role. However, Wenger believes that the Chilean is enjoying his new role up front.

"I think, yes, he likes the positions. You know how the players are, people like to play as strikers. If it doesn't work, they prefer their first position," the Arsenal boss added. "But when it comes off, of course, when they walk home with the ball under their arm, it's a good feeling and I think and hope that it gives him the taste for more. He has the qualities to play there, he has good movement, he is sharp. Maybe size-wise you could say he is not the tallest, but he is quite good in the air when he goes for it."