Both sides shuffled their packs for Sunday’s repeat of last season’s final – a fourth fixture in 10 days.
But Wenger resisted the temptation to rest Sanchez and the Chilean repaid him with a man-of-the-match display, scoring one and setting up the other for Per Mertesacker.
“He is lively and always dangerous,” Wenger said of the man signed from Barcelona for ??32m in the summer.
“Alexis has a change of direction, is incisive and penetrating, and has also a good fighting spirit.
“You look at the players who have that confidence and you are torn between when a player is that confident to keep him on playing or give him a rest.
“But when the players are confident it is important to keep them going,??especially when they have that physical potential.
“Sanchez recovers very quickly and he doesn’t look in our tests to have any??fatigue problem.”
The Gunners had won four of their last five in all competitions before slipping up at Southampton on New Year’s Day but Wenger was pleased with his players’ response.??
“We had a serious performance and we were in control,” the Frenchman added.
“Of course, as long as we don’t score the second goal, you never know, but it was a positive game and we created a lot of chances.”
Asked about January transfer business, Wenger confirmed the imminent departure of German forward Lukas Podolski,??and explained why he may sanction a loan deal for Yaya Sanogo.
“(Podolski) is going to Inter Milan,” Wenger said.
“He was frustrated because he didn’t get chance to play, I can??understand, but Sanogo is more in search for experience at the top level in the??Premier League. If he can get that, we will see.
“Sanogo is ready to play, but I have so many options up front it is difficult??for him to play.”