SAN DIEGO - Hunter Pence was missing from the clubhouse Friday night.

“Good news,” manager Bruce Bochy said. “He left.”

It’s good news because Pence, who is coming off hamstring surgery and hasn’t played since June 1, is ready to begin his rehab assignment. He’ll report to Triple-A Sacramento and play five innings both Saturday and Sunday in Round Rock, Texas.

He’ll be off Sunday and resume his schedule when Sacramento plays in New Orleans.

Bochy said Pence, because of his long run of inactivity, will need at least a week’s worth of games, about 30 at-bats. That could put him on target to rejoin the Giants when their next homestand opens, July 25 against Cincinnati.

“We said that last time last year, and we ended up bringing him up earlier than we thought,” said Bochy, recalling an abbreviated rehab assignment that ended when Pence urged Bochy in a text to promote him, calling himself a “ridiculous weapon.”

Pence returned to the lineup, went 2-for-3 and scored three runs to inspire an 11-2 win in Cincinnati.

“We’ll see how it goes. He’s missed a lot of time,” Bochy said.

Briefly: Joe Panik could begin his rehab assignment Sunday or Monday. He passed concussion tests and is waiting for final approval to play in games. … Matt Cain is slated to throw 90 to 100 pitches Friday night for Class A San Jose and rejoin the rotation Wednesday in Boston. … Matt Duffy (Achilles) is hitting and traking grounders and did a little running in San Francisco during the All-Star break. “It didn’t go as poorly as I thought it would.” But he was running at about 50 percent and isn’t close to playing ball again.

Giants lineup: CF Span, LF Pagan, 1B Belt, C Posey, SS Crawford, 3B Gillaspie, RF Blanco, 2B Pena, LH Bumgarner.

Padres lineup: C Norris, 1B Myers, RF Kemp, 3B Solarte, LF Betancourt, 2B Rosales, SS Ramirez, RH Cashner, CF Jankowski.

John Shea is a San Francisco Chronicle staff writer. Email: jshea@sfchronicle.com Twitter: @JohnSheaHey