Oakland Athletics minor league pitcher Sean Murphy died Monday, the team said. He was 27.
The Athletics said Murphy died in Arizona, but they did not provide additional details.
"The A's are deeply saddened by the tragic loss of Sean Murphy," vice president of baseball operations Billy Beane said in a statement. "Our thoughts and prayers are with his family and friends."
Murphy had been in the A's system for six years. A right-handed pitcher, he missed last season after having Tommy John surgery, and in February, he was suspended 50 games after a positive drug test.
"Sean was a competitor, a guy who wanted to pitch, wanted the ball in his hand," Athletics catcher Stephen Vogt said, according to the San Francisco Chronicle. "So much tenacity, he always gave you everything he had, and he was a fun guy in the clubhouse, always happy, always smiling, always in a good mood."
Added Oakland reliever Sean Doolittle: "I just can't believe it. Sean was from the other side of Philly, so we bonded and hung out a lot. I saw him a lot during the offseason, he was one of the familiar faces there all the time. I feel awful for his family."
In five minor league seasons, Murphy was 32-32 with a 4.26 ERA. He last played for Triple-A Sacramento in 2014.