The Liverpool boss took Keane off after 72 minutes with the striker still looking for a hat-trick goal. He has explained the thinking behind this decision.
"I also spoke to Robbie about the substitutions before the game. I said, 'I know I am changing you a lot but it is only because we need a different kind of player at certain stages of the game'," said Benitez.
"I didn't want to do it again against West Bromwich because, after his two goals, I was expecting the hat-trick. But we had to win the game, that was the most important thing, and Torres had to play too.
"I'm sure he was thinking, 'Why me? Leave me on the pitch', but I wanted to use the pace of Torres. They were playing high up the pitch.
"You can have sentiment as a manager sometimes but at 2-0 you have to be careful because one goal for them and it becomes very nervous at the end."
"I also spoke to Robbie about the substitutions before the game. I said, 'I know I am changing you a lot but it is only because we need a different kind of player at certain stages of the game'," said Benitez.
"I didn't want to do it again against West Bromwich because, after his two goals, I was expecting the hat-trick. But we had to win the game, that was the most important thing, and Torres had to play too.
"I'm sure he was thinking, 'Why me? Leave me on the pitch', but I wanted to use the pace of Torres. They were playing high up the pitch.
"You can have sentiment as a manager sometimes but at 2-0 you have to be careful because one goal for them and it becomes very nervous at the end."