Bobby Jenks, a two-time All-Star closer and World Series champion with the Chicago White Sox, is being treated for stomach cancer.
Jenks shared his condition from a Portugal hospital bed in an interview with MLB.com on Saturday, and the White Sox later sent their best wishes via social media.
"We stand with you, Bobby Jenks," the team wrote in an Instagram post.
The 43-year-old Jenks said he was planning to recover well enough to return for a second season as manager of the minor league Windy City Thunderbolts in Crestwood, Illinois.
"Now it's time to do what I got to do to get myself better and get myself more time, however you want to look at it," Jenks told MLB.com. "I'll tell you one thing: I'm not going to die here in Portugal."
Jenks helped the White Sox win the 2005 World Series, saving four games in six appearances during the postseason run. He was an All-Star in each of the next two seasons while saving 81 games overall in 2006 and 2007. Over the next three seasons, he averaged more than 28 saves.
He retired 41 consecutive batters in 2007, matching a record for a reliever.
Jenks saved 173 games for the White Sox over six seasons before finishing his career with 19 appearances in 2011 with the Boston Red Sox.