Back spasms ended his last game of the season, but he took the mound anyway for one last start. It was during a video shoot for Stand Up to Cancer. His batter was one of the toughest sluggers around, an eight-year-old cancer survivor named Justin.
"We're so excited to be taping this spot that's going to thank all of the fans for supporting Stand Up to Cancer through this fantastic program that Mastercard has done called Dine and Be Generous," said Kathleen Lobb, co-founder of Stand up to Cancer. Justin Miller was diagnosed with neuroblastoma when he was three years old and has since worked as an ambassador for St. Baldricks Foundation.
"Justin was featured in our SU2C telethon in September. ... He's been through an array of treatments," Lobb said. "One of the things his mom said on our show that really hit home is that it is absolutely the brand new research developments that are keeping young children like Justin alive."
That was more than enough to win over Lester.
When the opportunity came to shoot a video with Miller, the cancer survivor and two-time All-Star couldn't pass it up. He had been looking for an opportunity to get involved with Stand Up to Cancer and had already worked with several fundraising groups with a focus on helping kids. Lester said children can be some of the strongest cancer fighters.
"Kids are a little different than adults. I think adults get in those ruts of feeling sorry for themselves and really struggling with the day-to-day processes of things," Lester said.
"Obviously with my background with cancer I just wanted to be involved with it in some way," Lester said. "We had a son two years ago ... just to imagine if he went through what I went through, the pain and suffering he would have to deal with, it's something that we wanted to give back to."
The video of Miller and Lester was shot in tangent with a partnership with Mastercard and Stand Up to Cancer to raise money for a pediatric cancer "Dream Team". The Dream Team will be funded by both contributions made by the public in connection with the SU2C telecast and a significant donation from the St. Baldrick's Foundation. SU2C and St. Baldricks plan to raise over $14.5 million over the next four years. The Dream Team will be the first of it's kind to focus on pediatric cancer research.
"We have investigators at hundreds of institutions across the country working together to try to beat this disease," said Lobb.
It wasn't perfect timing for Lester who said he usually tries to do his cancer work during the regular season. Despite less publicity, Lester plans to stay busy this offseason raising more money for cancer research and sending out his message to others battling the disease.
That message is simple -- just don't quit.
"You can't quit, you can't stop fighting. If you're struggling that day, you just have to find a way to get through it and keep fighting," Lester said. "I know in the last five years we've made a lot of strides in the right direction as far as getting cures for different kinds of cancer. Hopefully we can continue to go in that right direction."
Gary Cotton is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.