That's it. The rest of the positions, including the Opening Day starting pitcher, are up for grabs.
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"There's plenty of opportunity out in front of us," said Green, beginning his second season as a Major League skipper after last year's 68-94 last-place finish in the National League West.
The prospective roster may be in the most flux since the team's inaugural 1969 season when Rafael Robles was the leadoff hitter, the late Chris Cannizzaro was the catcher and Dick Selma was the starting pitcher. San Diego lost a club-record 110 games that year.
It's a wide-open competition in Camp Padre. The three outfield spots are up for grabs, Green said.
"Out of the four guys we have out there coming back to the organization, there's Manuel Margot, Travis Jankowski, Alex Dickerson and Hunter Renfroe," Green added. "At-bats will play out accordingly for those guys. We also have a group of guys competing to be on the club out there."
At shortstop, it's two guys.
"[Newcomer] Erick Aybar and Luis Sardinas, battling it out in my mind," Green said.
"[Cory] Spangenberg and [Ryan] Schimpf are kind of slugging it out [at second]," he said. "They'll both try third base, too, and see if we're better with Solarte at second. We're just going to look at things."
Pitching is really up in the air. At this point, Green isn't close to naming an Opening Day starter or a closer. With the recent addition of Jered Weaver on a one-year, $3 million deal in free agency, the veteran starters include Clayton Richard, Trevor Cahill, Jarred Cosart, Luis Perdomo and Craig Stammen.
Stammen started for the Nationals in 2009-10 and has worked out of the bullpen ever since. He spent the entire 2016 season in the Indians' Minor League system. Cahill hasn't started regularly since he flamed out with the D-backs in 2014. He was used exclusively by the Cubs out of the bullpen the past one-plus seasons.
"We'll have a host of guys to choose [an Opening Day starter] from, but we're not ready to declare yet," Green said.
As far as the back end of the bullpen is concerned, the candidates are Brandon Maurer and Carter Capps. Capps was supposed to close for the Marlins last year, but he blew out the UCL in his right elbow early in Spring Training, underwent Tommy John surgery last March 8, and missed the season.
Since recovery time from that surgery is 12-18 months, it's not likely Capps will come out of camp healthy enough to pitch. Maurer saved 13 games for the Padres last season after Fernando Rodney was traded to the Marlins.
"We'll probably introduce [Capps] into the Cactus League after he throws some games on the back fields so he's not in an amped up environment too quickly," Green said. "Basically, I'm telling you we don't have a lot decided right now. We have a lot of work to do."