Cash became friends with Farrell when Farrell served as the Red Sox pitching coach and Cash was a reserve catcher for the team.
When Cash was asked about his reaction to the news, he told reporters: "Yeah, I was a little stunned. ... I tried to call; [sent] him a text. Obviously, he's pretty well connected in this game. A lot of people have a ton of respect for John. And knowing him and that he's a pretty strong guy, he'll get through this."
Farrell will undergo treatment in the coming days. He had a mass removed during hernia surgery Monday in Detroit. Bench coach Torey Lovullo will manage the Red Sox on an interim basis.
Bill Chastain is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.