Guzan says Lerner is always welcome at the club when he visits from the US.
"He's invested a lot into the club and as players, that's all you can ask," said the goalkeeper. "On a personal level, he's at the training ground and he's at the stadium.
"I know the fans really take to him. The players really take to him. He's very personable, approachable.
"The last few years when we've been going through some rough patches, he's come and given everyone his backing. It's nice to have that as a player."