SAN FRANCISCO -- The bullpen gate swung open and out walked the Core Four -- Jeremy Affeldt, Santiago Casilla, Javier López and Sergio Romo -- a fitting entrance for their joint induction into the Giants’ Wall of Fame on Saturday afternoon at Oracle Park.

The foursome were key cogs in Bruce Bochy’s bullpen during the Giants’ three World Series runs in 2010, ‘12 and ‘14, combining to record a 1.14 ERA over 78 2/3 playoff innings. They tallied eight saves and went a combined 7-1 over 98 appearances in those three postseasons, making them one of the most dominant relief quartets in franchise history.

Their accomplishments were celebrated during a special pregame ceremony that was attended by several former Giants, including Buster Posey, Hunter Pence, Ryan Vogelsong, Brian Wilson and George Kontos.

“What they brought to the field was an intensity, a competitiveness and just a desire to get that guy out that was standing in front of him on a nightly basis,” Vogelsong said. “It didn’t matter how tired they were, how many times they’d been up. It was just, ‘Give me the ball, I’ll get the guy out in front of me.’

“I also want to say thank you guys so much for being unbelievable teammates. We all saw what happened out here, what you guys did on the field, but what fans and everyone else didn’t get to see was what y’all meant to us in the clubhouse. We definitely are not the team we are without you guys. You were the bond that held us together.”

Romo, the slight right-hander with a wicked slider, struck out Tigers superstar Miguel Cabrera looking for the final out of the 2012 World Series, while the left-handed Affeldt earned the win in Game 7 of the 2014 Fall Classic after firing 2 1/3 scoreless innings in relief to set up Madison Bumgarner’s legendary five-inning save against the Royals.

The hard-throwing Casilla also enjoyed a run as the Giants’ closer, while López -- now a broadcaster for NBC Sports Bay Area -- made his living as a lefty specialist.

“At the end of the day, it’s very fitting that it’s us four sharing this honor,” Romo said.

Posey drew laughs as he shared his memories of catching each of the relievers:

“When I think of Affeldt, I think of an 0-0 count, I call a curveball and I’m thinking he’s just going to flip this thing in here and get a strike. I see him start to grimace, really tighten his grip and the ball barely bounces in front of the grass and hits me in the neck.

“When I think about Casilla, I think about putting the sign down, him shaking seven times and then agreeing to the first pitch that I called, which was the sinker.

“Romo, talk about shaking somebody off. I still have nightmares sometimes in Detroit. He shook away and decided he’d blow 75 [mph] past Miguel Cabrera.

“Javy, I really don’t really have much for you. I thought long and hard. You were pretty easy.”

After the unveiling of their Wall of Fame plaques, the group gathered in front of the mound and each threw out a ceremonial first pitch to four current Giants relievers: Tyler Rogers, Taylor Rogers, Camilo Doval and Ryan Walker.

“We’re brothers,” López said. “I just start to smile every time I see these guys. It’s been a great couple of days.”

Current Giants skipper Bob Melvin, who managed López in Arizona and Romo and Casilla in Oakland, said he remembers how daunting it could be to face the quartet when they were pitching out of the same bullpen in San Francisco.

“Not a great feeling because you knew they were deep,” Melvin said. “They all seemed to play better than their stuff. Their competitiveness is what I remember the most. … When you get a group together like that, they kind of feed off each other and probably pitch better because of how tight they are and how much success they had. It’s a special group.”