Red Sox manager John Farrell said Friday that he had a "very treatable" form of cancer and would take a medical leave to deal with lymphoma.
The 53-year-old Farrell said Boston bench coach Torey Lovullo will run the team in his absence.
The Red Sox were in last place in the AL East with a 50-64 record going into Friday night's game against Seattle at Fenway Park.
Farrell guided Boston to the World Series championship in his first season in 2013. He previously managed the Toronto Blue Jays.
On Tuesday, Minnesota Timberwolves coach Flip Saunders said he is being treated for Hodgkin lymphoma, and his doctors consider it "very treatable and curable." His plans were to remain coach and team president while being treated.