"We'll get an MRI tomorrow, but he's looking at five to seven days," Bochy said. "I haven't had a chance to talk to [general manager] Bobby Evans, but I think it is pretty evident we're going to have to get somebody to help out here."
After the collision, Pena initially looked OK. He remained in the game and stayed at second base through the fourth inning. Pena said his ankle continued to swell and Conor Gillaspie opened the top of the fifth in his spot in the batting order.
Newly promoted Giant Ruben Tejada moved to second and Gillaspie took over third for the remainder of the game.
"I was trying to keep in the game and battle and be able to play, but at some point it was so stiff that I couldn't move," Pena said.
Pena would be the fifth Giants player just in the infield to hit the disabled list if his ankle injury is serious. The first-year Giant who had his contract purchased from Triple-A Sacramento on June 10 entered Wednesday hitting .412 in 34 at-bats. In addition, he recorded six multihit games while being versatile enough to play at third, shortstop and second.
Bochy said he'd have more information on Pena's status Thursday, following his scheduled MRI.
Justin Wise is a reporter for MLB.com based in the Bay Area. This story was not subject to the approval of Major League Baseball or its clubs.