SAN FRANCISCO -- The Giants made several roster moves Friday, placing Kelby Tomlinson on the 15-day disabled list with a sprained left thumb and calling up infielder Ramiro Pena, while also transferring reliever Sergio Romo to the 60-day DL.
Tomlinson injured his thumb Wednesday against the Red Sox on a diving play in the seventh inning. News of the injury caught both Tomlinson -- who finished the game and even completed a postgame workout -- and the team off guard.
"He woke up [the next morning] and it was killing him," Giants manager Bruce Bochy said. "He called [head athletic trainer] Dave Groeschner and had an MRI done. Sure enough, he had a moderate strain, so he has to go on the DL."
Bochy said Tomlinson will be sidelined for two to three weeks and will wear a splint for the next two weeks before beginning a rehab process.
"Kelby was as surprised and shocked as we were when we found out," Bochy said.
Pena will fill Tomlinson's role as a utility infielder. He hasn't played in the Majors since 2014 with the Braves and hit .304 in 49 games this season with Triple-A Sacramento. He spent all of last season in the Padres' Minor League system, hitting .308 for Triple-A El Paso, and wondered if he'd get another shot in the Majors.

"I had a good year last year and I didn't get a chance," said Pena, who added he wasn't expecting to get called up. "This year I was starting to think about it. Thank God I got the call."
The 30-year-old has spent parts of six seasons in the Majors with the Yankees and Braves. He wasn't in the lineup Friday against the Dodgers, but Bochy said the switch-hitter's experience and versatility is an asset.
Romo's been on the DL since mid-April with a flexor strain in his right elbow. He made three rehab appearances in Sacramento in May, but felt "tenderness" in the elbow, forcing San Francisco to shut him down.
Bochy said the team hopes Romo, who played catch from 90 feet Wednesday, can throw off a mound Saturday.
• Outfielder Angel Pagan is scheduled to begin a three-game rehab assignment in Triple-A on Saturday. He'll play three straight days, rest Tuesday, and if all goes well, could be back in the lineup as early as Wednesday, per Bochy.
• Bochy said right-hander Matt Cain was scheduled to throw a bullpen session Friday, and there's a "possibility" he could start Monday against Milwaukee, adding he won't need to go on a rehab assignment.
• The Giants also made a minor trade late Thursday night, acquiring outfielder Shawon Dunston Jr. from the Cubs for cash or a player to be named. He's the son of Giants special assistant and former Cubs and Giants shortstop Shawon Dunston and has never played above Class A Advanced since being drafted in 2011.