SCOTTSDALE, Ariz. -- You'll hear it often over the next six weeks: The Giants are embracing competition.

But when it comes to the race to be the backup catcher, this isn't quite a wide-open field. The Giants planned to have three players compete to be Buster Posey's backup, but Aramis Garcia had hip surgery last week and likely will miss the entire season. Garcia might have been the frontrunner entering the new year, but manager Gabe Kapler said Tuesday that two newcomers to the organization, Tyler Heineman and Rob Brantly, will now fight for that Opening Day job.

Heineman and Brantly are both in camp as non-roster invitees. The Giants also have Chad Tromp, top prospect Joey Bart and 20-year-old Ricardo Genoves on the non-roster list, but for now, this appears to be a two-horse race.

"Obviously it's a blow to lose Garcia. It's also an opportunity for somebody to step up and take control of that backup position," Kapler said Tuesday a few hours before catchers reported for physicals. "If we break with either Brantly and Buster or Heineman and Buster, it'll give us a good opportunity to face a tough right-handed pitcher and get Buster off his feet once in a while. Obviously, no matter who the backup is, our game plan will be to have Buster on the field as much as possible."

The Giants do not appear poised for a repeat of last summer, when Stephen Vogt proved to be one of their more reliable hitters and at times nearly was in a timeshare with Posey, who struggled to reach his past heights at the plate. But Brantly and Heineman do have something in common with Vogt, now with the Arizona Diamondbacks. They both hit left-handed, with Heineman also being a switch-hitter.

Heineman, 28, got 11 at-bats with the Miami Marlins last year. He tore up the hitter-friendly Pacific Coast League, posting a .400 on-base percentage and hitting 13 homers and 17 doubles. Heineman has 208 walks and just 266 strikeouts in eight minor league seasons, so he fits well with what the Giants are teaching their hitters.

Brantly is also known for having a good sense of the strike zone and he posted a .404 OBP in Triple-A last season. The 30-year-old has a slight leg up on the competition having spent last season in the Phillies organization. Kapler said Brantly is an excellent teammate and smart game-caller.

The real intrigue comes further down the line.

Genoves, signed out of Venezuela, was added to the non-roster list Sunday to give the Giants another glove. He put up good numbers in Salem-Keizer and Augusta last year before the Giants sent him to the Arizona Fall League. Tromp is just 24, which is young for a non-roster catcher, and the Giants are excited about the organizational depth they have in those two.

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Then there's Bart, who is on track to be the next face of the franchise. The 23-year-old is supposed to start the year in Triple-A and Farhan Zaidi and Kapler both have said Bart needs more reps, but there's little doubt he'll be one of the stories of camp. Bart is not part of the competition to back up Posey, but his locker is just about 10 feet away in a new clubhouse.

"That is by design," Kapler said. "We want those guys to be spending time together."