SCOTTSDALE -- Matt Cain will miss at least 10 days after having a cyst removed from his right upper arm. Cain had the procedure Thursday morning in San Francisco, with team doctor Ken Akizuki doing the surgery.
Trainer Dave Groeschner traveled with Cain to start the rehab process.
General manager Bobby Evans said Cain had a different cyst removed from the arm in the offseason. The Giants have not ruled Cain out for the start of the regular season.
"It's too early to say," Evans said. "It's early so it gives him a chance to catch up."
The 31-year-old right-hander has made just 26 starts the past two seasons because of injuries. He had bone chips removed from his pitching elbow in 2014 and was a late scratch from the rotation at the start of last season because of forearm tightness.
When Cain returned he posted a 5.79 ERA in 13 appearances, but the Giants were encouraged by his last start.
They declared at the start of camp that Cain would be part of the rotation, but just in case, Chris Heston has been asked to prepare as a starter, not a reliever.