The 2007 NL Cy Young Award winner, who was 1-9 with a 4.72 earned-run average with Boston this season, will start Sunday night's game against the Dodgers in San Francisco.
"It's great to be reunited with Jake," Bochy said by text message. "Look forward to working with him again."
San Francisco received cash from Boston and is sending right-hander Heath Hembree and lefty Edwin Escobar to the Red Sox in the swap. Both players were optioned to triple-A Pawtucket.
Catcher A.J. Pierzynski signed with the St. Louis Cardinals, choosing them from among several suitors, 10 days after being released by the Red Sox. The veteran didn't divulge what other teams showed interest in him, but said playing for a contender was a priority.
"You want to try and find a team that can win. You don't want to go to the team that's in last place and just kind of play out the string," said Pierzynski, 37, who was in the starting lineup and batting sixth for the Cardinals' afternoon matchup against the Chicago Cubs.
Pierzynski, now with his sixth team in 17 seasons, spoke with St. Louis Manager Mike Matheny on Friday before signing and expressed his desire to continue playing and willingness to accept whatever role was best for the team.
Matsuzaka on the disabled list
The New York Mets put pitcher Daisuke Matsuzaka on the 15-day disabled list, retroactive to July 25, with right elbow inflammation, and selected pitcher Buddy Carlyle's contract from triple-A Las Vegas.
Matsuzaka returned to New York on Friday for an MRI exam after experiencing soreness in the elbow. He is 1-0 with one save and a 3.25 ERA in 19 games in relief this season and 2-3 with a 4.24 ERA in nine starts this year.