The Spanish striker has already made 33 appearances this campaign and Benitez feels it is coming to a point in the season where he will need to take a load off.
"Fernando is one of the players who needs to rest. Two or three players have been playing too many games in the last weeks and months," Benitez told reporters.
"Managing that was going well but against QPR it didn't work. Some of the players couldn't get to the level we were expecting.
"Without talking about names, if you have another striker you can play with two strikers if you need to.
"Or if you want to rest a striker then you can do that and at the moment we are a bit short."