Carragher was given an injection on Wednesday to try and cure the problem and has been left out of the England squad to face Argentina to aid his recovery.
The way Carragher has continued to put in one excellent performance after another despite his ankle problem has earned him praise from his grateful manager.
"Carra has had a problem for some time and now we are trying to protect him," said Benitez.
"He is a brave player and he never wants to come off or miss a game. The last thing we wanted was for him to play in a friendly and risk us losing him for a long time.
"With rest he can prepare for our next games. He has the character you want as a manager, which makes him so important."
