"I talked to him a little bit already," Lester said after the Cubs' 6-5 victory over the White Sox. "It was good. He seems pretty positive. Everything seems pretty positive, so that's good."
Lester also took to Twitter soon after the game to express his support for Farrell.
"He's in a good place for it," Lester said of the Red Sox's medical staff and Massachusetts General Hospital. "Obviously, it's one of the better places, if not the best place in the country to be [to get treatment] if you do have cancer. He's in good hands. I know those doctors pretty well. It seems like he's doing well."
Lester, who still stays in touch with Red Sox medical director Dr. Larry Ronan, said Farrell will have a great support staff, similar to what the pitcher had when he had to deal with his battle.
"I don't really think you give John too much advice," Lester said. "If you know John, he's pretty strong-willed. I would imagine he'll be fine. I'm sure it's a little bit of a blow for his family. I'm sure he'll be fine through this whole process."
There isn't any way to prepare for this, Lester said.
"It's one of those things you have to just ride out," Lester said. "You have to do what the doctors tell you to do. I don't know the details of what he'll be going through or anything like that. I don't know the type. I just know it's lymphoma -- it can be a million different things. It sounded pretty curable, it sounded pretty positive from what I read and what I saw. That's the most important thing.
"I don't think you can ever prepare for a situation like that. You just have to kind of grind through it."
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings. You can follow her on Twitter @CarrieMuskat and listen to her podcast. This story was not subject to the approval of Major League Baseball or its clubs.