Chelsea are up against Fulham in the London Derby at Stamford Bridge tonight.
Benitez is under pressure to produce results, and is said to regard Mikel as too defensive and not creative enough to provide opportunites for Torres.
Mikel was missing from preperations for the match, and could be replaced by Oriel Romeu, who came on for him against Manchester City on Sunday.
The new Chelsea coach spoke out on Torres as well, insisting that the 28-year-old can return to form.
"He's not exactly the same player now, because he was at maximum level at this time [at Liverpool]," Benitez said of his fellow Spaniard.
"But I think he can come back. How close? I don't know. It depends on the rest of the team. I'm sure he can improve, but the team has to help him."
Torres has scored just 19 goals in 88 games for the European champions, but Benitez says he can see what the striker needs.
"The first thing is to give him some confidence, instructions as to how he can do things in a different way, improve him a little bit physically," the manager said.
"You need to be stronger in defence, regain the ball easier and then you can create your own chances. That will benefit Torres.
"Players with mobility, quality ... we can improve all these things."
When asked if he has been under pressure to pick record signing Torres by club owner Roman Abramovich, Benitez said: "It's easy at the moment because [Daniel] Sturridge is still injured."
Sturridge is Chelsea's only other recognised centre-forward, and it seems likely the club will make some signings in the January transfer window.