Jeffrey Becker-USA TODAY Sports

Chicago Cubs great Ryne Sandberg revealed Monday that he is beginning treatment for metastatic prostate cancer.

The Hall of Fame second baseman spent 15 of his 16 major league seasons with the Cubs, along with 13 games at the start of his career for the Philadelphia Phillies (1981).

Sandberg, 64, said in an Instagram post that he was diagnosed last week. One of the photos in the post shows Sandberg standing and giving a thumbs-up gesture while hooked to a machine in a hospital room.

"I have begun treatment, and I am surrounded by my loving wife Margaret, our incredibly supportive family, the best medical care team and our dear friends," Sandberg wrote. "We will continue to be positive, strong and fight to beat this. Please keep us in your thoughts and prayers during this difficult time for me and my family."

Sandberg was the 1984 National League MVP, when he batted a career-high .314 with a major league-leading 19 triples and 114 runs scored as well as 19 home runs, 84 RBIs and 32 stolen bases.

He also earned the second of his nine career Gold Glove awards that year. He was a 10-time All-Star selection and a seven-time Silver Slugger honoree, batting .285 with 282 home runs and 1,061 RBIs in his 2,164-game career.

Sandberg, who was elected to the National Baseball Hall of Fame in 2005, also spent parts of three seasons (2013-15) as the Phillies' manager. The team went 119-159 in that stretch.

More must-reads:

TODAY'S BEST
Suns to hire ex-NBA champion as new head coach
MVP Jokic, Nuggets blow out Timberwolves on road in Game 3
Panthers dominate Bruins again to take 2-1 series lead
ESPN has big plans for Caitlin Clark's WNBA debut
Angels superstar explains why he chose not to play through knee injury
Bears make big, but not surprising Caleb Williams announcement
Cardinals to sign WR who commanded extensive interest
Jayson Tatum refutes narrative that Celtics are a 'superteam'
Watch: Kyle Busch crashes in Truck Series race at Darlington
Oilers work overtime to tie Canucks at 1-1
Broncos release former Super Bowl champion WR
Former NBA big man sentenced to 40 months in prison
Peyton Manning reveals Bill Belichick's role on 'ManningCast' for this season
NBA Hall of Famer questions Knicks longevity in face of high playoff workloads
Falcons rookie QB Michael Penix Jr. details first interaction with Kirk Cousins
Insider reveals Mike Budenholzer's humongous contract figures to be Suns HC
Watch: Novak Djokovic accidentally struck, knocked down by metal water bottle
Legendary Cowboys HC clarifies misunderstanding regarding HOFer's death with same name
Raiders HC names leader in Aidan O'Connell, Gardner Minshew competition
Former MLB infielder Sean Burroughs dies at 43 years old

Want more Cubs news?

Join the hundreds of thousands of fans who start their day with Yardbarker's Morning Bark, the best newsletter in sports.