A £60 million deal had been agreed between Arsenal and Manchester City for the Chilean forward during the last few days of the transfer window, however the deal fell through after the Gunners failed to sign a replacement.
“He is still a bit short physically,” Wenger said after the game to BBC Sport. “He will be quickly back to his best. He will win the fans back, and win them back very quickly.
“Alexis Sanchez is very focused on the Premier League and the Europa League and he wants to do well.”
Welbeck making good progress
It was a comfortable victory for Arsenal yesterday thanks to two goals from Danny Welbeck and one from Alexandre Lacazette securing the points, and the Arsenal boss was asked about both after the game.
On Welbeck, the boss said: “I’m pleased with his performance, I kept faith in him and overall I think he is getting stronger and stronger and more confident. Confidence plays a big part in his game and I loved his finishing on his second goal.”
After missing half of last season through injury, a strong pre-season has been key for the Englishman, who also scored during the international break, and Wenger believes things are looking bright for Welbeck.
“If he can add the finishing, he’s a team player as well, he is loved by his partners, so that’s a lot of positives.”
Wenger promises strong team for Europa League
On the topic of Lacazette, Wenger explained his decision for leaving him out of the previous fixture against Liverpool, whilst also praising his class on the pitch on Saturday.
“I kept him out because I thought you can take some time to adapt, but I agree, he is getting stronger and stronger from game to game.
“Physically he worked very hard today," Wenger continued. "He still suffered a little bit in the second half, but physically he’s getting better in every game. And on the football front you see he is a great player.”
Next up for Arsenal is their first fixture in this seasons’ Europa League against 1. FC Köln, and Wenger was asked about the possible starting eleven.
“It will be a Premier League team," he insisted. "Some players will come in of course, because many players played twice for the national team, and then again today. So two or three will not be in the squad, but most of them will play.”