Sanchez, out of contract at the end of the season, is expected to leave the north London club during the transfer window with both Manchester City and Manchester United in the race to sign him, PA Sport reported.
The 20-year-old Brazilian forward Malcom – who has netted seven times for Ligue 1 side Bordeaux this season – has been linked with a move to the Emirates Stadium to fill Sanchez's boots.
And Wenger, whose side travels to Bournemouth on Sunday as the Gunners return to Premier League action, admitted that the Chile international will only be allowed to leave if the London side can get a new signing over the line.
The Frenchman said, "Of course I want a quick resolution.
"Is he [Sanchez] replaceable in the way that we find exactly the same player? Certainly not, but there's always a way to find a different balance.
"Alexis is an exceptional football player, he's a world-class player and if that happens [and he leaves] we have to find a different balance in the team.
"I have had many conversations about him and we talked about the fact that people are always observing you with a microscope when you're on a short-term contract, but I've never questioned his professional attitude when he's on the football pitch."
Reflecting on United's reported interest in the former Barcelona forward, Wenger added, "A bidding war is always beneficial to the club who can take advantage of it. We are not in that.
"I maintain what I've said many times. Normally, he should stay here until the end of the season but we'll see."