Pennant was sent off in the second half for a second bookable offence.
Benitez said: “I have no complaints about the decision. It was correct.
“Hopefully Jermaine will learn from this experience. Maybe it will produce something positive for the future, the tackle in that position was just not needed.
“It is difficult to understand why he did it, we had talked to him about staying on his feet and not making rash challenges. We were even talking on the bench about taking him off, but we just did not get the time to do it.”
