"I travelled to Geneva with Sir Alex Ferguson for the UEFA coaches conference last week. He's a nice person," Benitez said.
"We didn't speak about the game this Sunday, but we were talking a lot about the Champions League. He wanted information on Villarreal," he added.
Benitez continued, "I remember Sir Alex sent me a letter of congratulation when we won the Champions League, praising the tactical changes we made at half-time."
"He was saying it was a fantastic move to put Didi Hamann on. Some people may just say well done when you win a big trophy, but the difference with him is he's always thinking as a manager. I like this and his letter meant more to me because of it," the Reds boss added.