San Francisco ? Bobby Bonds underwent open-heart surgery Friday, the latest medical setback for the former All-Star slugger.

Bonds’ son, Barry, left the San Francisco Giants to be with his 57-year-old father for his operation at a Bay area hospital.

Jim Davenport, Bobby Bonds’ best friend and former teammate, visited him in the hospital Friday night.

“I can’t tell you anything except he went through the operation fine,” Davenport said. “They said they’d keep him in intensive care five days and then he’ll stay in the hospital another five days. This has nothing to do with the cancer. He was having problems breathing. They said he had a thick wall around his heart.”

Barry Bonds rushed out of Pacific Bell Park after Thursday afternoon’s game on his 39th birthday. He missed Friday night’s game against San Diego and the Giants said they weren’t sure when he would return to the team.

Team spokesman Jim Moorehead said Bobby Bonds, who has been battling lung cancer, had been in the hospital for at least three days but possibly longer. No further details were immediately available.

Bobby Bonds has been dealing with numerous ailments recently. In early June, he was being given oxygen to fight pneumonia and spent some time in the hospital.

He underwent surgery on a brain tumor in April and has had the lung cancer, but still had the energy to go spring training and see his son and the Giants play at home this season.

Manager Felipe Alou said he expected to hear from his slugger late Friday or early today about whether he’d play in tonight’s game.

“It says something about him,” Alou said. “When I came here, I heard a lot of things about how selfish a player he was. It’s turned out to be quite the opposite. He actually wanted to go to Bobby Bonilla’s father’s funeral in New York, but he couldn’t do it because it would put too much strain on him.”

Bobby Bonds is known more for his son now than his own exploits. But he was a three-time All-Star and the MVP of the 1973 game.

Bonds became the second National League player to hit 30 homers and steal 30 bases in the same season in 1969 with the San Francisco Giants. Willie Mays, his close friend and godfather of Barry, was the first to do it.

Bobby Bonds joined the 30-30 club four more times in his 14-year career. Barry Bonds has also done it five times; no other player has reached the mark more than three times.

Bobby Bonds hit 332 home runs and stole 461 bases in his 14-year career. He hit .268, had 1,024 RBIs and won three Gold Glove awards as an outfielder.

A native of Riverside, Calif., he signed with the Giants in 1964 out of high school. He played seven seasons with San Francisco and has remained with the Giants after retiring. He served as the club’s hitting coach from 1993-96 and since then has been a special assistant to general manager Brian Sabean.