Twins bench coach Mike Bell has been diagnosed with kidney cancer, manager Rocco Baldelli announced Wednesday.

The condition will keep Bell away from training camp this spring and out of the dugout for at least part of the 2021 season.

Bell underwent surgery January 28 in Arizona to remove a cancerous tumor in his kidney and other tissue around it, Baldelli said, and was released from the hospital the next week to recover at home. He faces several weeks of chemotherapy and other treatments, the Twins manager said, but doctors believe Bell's prognosis is good.

Still, it's too early to know how long Bell will be away from the team, Baldelli added.

"He's very, very optimistic and also very encouraged and waiting for his return to the dugout," Baldelli said in a video call with reporters. "The situation is obviously serious, but Mike has handled this with great courage. He's recovering, doing great, and is looking forward to the next part of his recovery. Believe me, he's already plotting his return."

The 46-year-old Bell, a former major league infielder and brother of Reds manager David Bell, joined Baldelli's staff in 2020 and helped lead the Twins to the American League Central Division championship.

After falling ill in January, a cancerous tumor was discovered in his kidney, requiring surgery to remove.

As bench coach, Bell is in charge of organizing the Twins' spring training workouts, a task that now falls to staff assistant Nate Dammann. He also is Baldelli's chief strategist and advisor before and during games; Baldelli has not yet named an interim replacement for that part of the job.

Bell, who worked in the Arizona Diamondbacks' player-development department for a decade after retiring from his playing career in 2005, lives in the Phoenix area with his wife and two children. His father, Buddy, and his grandfather, Gus, are both former MLB players and managers as well.