Sanchez was only a substitute to start the first leg of the Carabao Cup semi-final amidst speculation that a move to Manchester City is close to being finalised.

Sanchez then played the last 25 minutes, and Wenger insisted that his team selection "had nothing to do with the transfer market."

"I don't have to justify every decision I make, you know. I made over 1,000 games and over 1,000 teams and I got it every time wrong, but I have to make a decision," Wenger said.

With Mesut Ozil out injured, the Arsenal boss started with a front three of Alex Iwobi, Danny Welbeck and Alexandre Lacazette -- the exact same trio who drew widespread praise for their gritty performance in the 0-0 Premier League draw at Stamford Bridge this season.

Asked if he remains confident that Sanchez will stay at the club until the summer, when his contract expires, Wenger said: "Yes, that's what I want.

"I want him to stay for longer because he's a very important players for us. When he came on tonight, you could see that he created straight away danger.

"We have to accept as well when you play so many games and Sanchez plays every game that sometimes a breather in the middle of the season helps a little bit."

Wenger also staunchly defended Sanchez's attitude and his ability to focus on his job despite all the speculation about his future.

"People don't know Alexis well -- this is a guy who is completely focused to play football. Have you seen how he came on today, how he warmed up? Like a player who wants to play football," Wenger said.

"He can make a difference between what's going on outside and what's going on on the football pitch, with facts, not psychological theories. The fact is when you turn up on the pitch, you play football and you give 100 percent. That's what he does."

The only negative for Arsenal on the evening was Jack Wilshere limping off with an ankle sprain, although Wenger didn't think the injury was "too bad."

"He has an ankle sprain, the first look at it was not too bad. But of course for Sunday I think he will be short," Wenger said. "How long he will be out, I don't know."

Wilshere limped off in the 57th minute after getting hit by a cross on his foot, which twisted awkwardly.

Wilshere has a long history of serious ankle injuries, but Wenger said this was not the same foot that was fractured late last season.

"It's a shame to lose him when he's in such a good form. It was by blocking the shot that turned his ankle," Wenger said. "It's his good ankle so I'm quite positive."