SAN FRANCISCO -- The Giants unveiled the initial list of players who will be eligible to play for them in the pandemic-shortened 2020 season on Monday, with 51 of the available 60 spots in their player pool now officially accounted for.

The contingent includes 33 of the Giants’ 40-man roster players, as well as 18 non-roster invitees. The nine open spots will create more flexibility for the Giants, who will be able to evaluate their depth in the coming weeks and potentially add more players via trades, free-agent signings or waiver claims down the line.

• FAQ: Roster and transaction rules for 2020

The Giants are set to report to Oracle Park for training camp by Wednesday, with their first official workout tentatively scheduled for Friday.

As expected, Joey Bart, Marco Luciano and Heliot Ramos -- the club’s top three prospects, according to MLB Pipeline -- have been invited to train alongside the Giants’ Major League players, giving them an opportunity to further their development in a competitive environment this year.

Hunter Bishop, the Giants’ 2019 first-round Draft pick, was in line to join them, but he tested positive for COVID-19 in Arizona on Friday and will now be required to quarantine for 14 days. Bishop has “very mild” symptoms and is improving, according to president of baseball operations Farhan Zaidi.

• FAQ: All you need to know about 2020 season

In a procedural move, the Giants also released and re-signed four non-roster players on Sunday: Trevor Cahill, Pablo Sandoval, Yolmer Sánchez and Billy Hamilton. All four are part of the Giants’ player pool and are expected to be strong candidates for the 30-man Opening Day roster. Zaidi said Sunday’s transactions largely resulted from the need to tweak performance bonus structures in each of the players’ original contracts.

The four veterans will still have the ability to opt out of their contracts with the Giants if they are not added to the 40-man roster before Opening Day. San Francisco cleared two roster spots on Sunday by transferring right-hander Tyler Beede (Tommy John surgery) to the 60-day injured list and outrighting right-hander Enderson Franco.

Below is the Giants’ player pool (italics indicates non-roster invitee):

Catchers (4): Buster Posey, Joey Bart, Tyler Heineman, Rob Brantly

With Aramis Garcia (right hip surgery) out until at least late August, the backup catcher competition is expected to come down to Brantly and Heineman, both of whom signed Minor League deals with the Giants earlier this offseason. While San Francisco will be allowed to carry 30 players on its Opening Day roster, Zaidi said he isn’t inclined to use one of the extra spots on a third catcher, making it unlikely that Bart will open the year in the Majors.

“I think it's very possible, maybe even likely, that we would just start with two catchers,” Zaidi said. “I wouldn't rule out a third, but it's not an active point of conversation.”

Infielders (12): Abiatal Avelino, Brandon Belt, Brandon Crawford, Maurico Dubón, Wilmer Flores, Evan Longoria, Donovan Solano, Zach Green, Marco Luciano, Darin Ruf, Yolmer Sánchez, Pablo Sandoval

The Giants will likely have some sort of rotation at second base, where Dubón, Flores, Sánchez and Solano are expected to compete for at-bats. Dubón will also be an option in center field and at shortstop, which could help free up playing time for others at second. Now that Sandoval has completed his rehabilitation from Tommy John surgery, he should be ready to reprise his role as a backup corner infielder and give the Giants another option at designated hitter. Another player who should benefit from expanded rosters and the arrival of the universal DH is Ruf, who was making a serious push for the Opening Day roster before camp shut down in March.

Outfielders (10): Jaylin Davis, Alex Dickerson, Steven Duggar, Joe McCarthy, Hunter Pence, Austin Slater, Mike Yastrzemski, Billy Hamilton, Heliot Ramos, Joey Rickard

Dickerson and Pence were poised to platoon in left field, but they could now see time at the DH spot as well, especially since the Giants will be looking for ways to manage their workloads and keep them healthy. Center field remains a bit thin for San Francisco, but Hamilton could prove to be a particularly valuable asset under the new rules for the 2020 season. Extra innings will begin with a runner on second base, making the speedy Hamilton a fascinating weapon for manager Gabe Kapler to deploy over the course of the 60-game regular season.

Pitchers (25): Shaun Anderson, Tyler Anderson, Sam Coonrod, Johnny Cueto, Jarlín García, Kevin Gausman, Trevor Gott, Dany Jiménez, Conner Menez, Wandy Peralta, Dereck Rodríguez, Tyler Rogers, Jeff Samardzija, Sam Selman, Drew Smyly, Andrew Suárez, Tony Watson, Logan Webb, Trevor Cahill, Tyler Cyr, Rico Garcia, Luis Madero, Carlos Navas, Trevor Oaks, Andrew Triggs

The shortened ramp-up to Opening Day will likely blur the traditional distinction between starters and relievers, especially at the beginning of the season. The Giants will explore unconventional paths to get to 27 outs, with openers and tandem starts among the possibilities.

“There's a high likelihood that when we break camp, these guys are only prepared for three innings, maybe even three-plus,” Kapler said. “So we're going to have to take down games with a starter and then some bulk options. None of that is set in stone, obviously. We really want to get our eyes on the players before we make that determination, but it's not going to look like our normal opening series where you might have three starters, all of them capable of taking down six innings and 85 to 90 to 100 pitches. There is no chance of that happening. We just have to set expectations reasonably.”