MIAMI -- The Marlins on Monday placed right-hander Elieser Hernandez on the 10-day injured list with right biceps inflammation. Hernandez, who exited his season debut after 34 pitches on Saturday, was scheduled to see a doctor before deciding the next course of action.

First baseman/outfielder Garrett Cooper also landed on the IL with a reaction to the second dose of the COVID-19 vaccine. That stint can be as many days as he needs to recover, with no minimum requirement.

As corresponding roster moves, Miami recalled right-handers Nick Neidert (the club’s No. 12 prospect, per MLB Pipeline) and Jordan Holloway (No. 24). Neidert, who lost out on the fifth-starter spot in 2020, went on to make four multi-inning relief appearances as a rookie last season. This spring, he kept his pitch count up despite once again entering games out of the bullpen. Both Neidert and Holloway were on last season's extended Opening Day roster, and later in the season were both put on the COVID injured list.

"Nick's a guy that got hurt by 2.0 [Summer Camp] and COVID last year," Marlins manager Don Mattingly said during a Zoom call. "He never seemed to recover after he got COVID. He had a really good 1.0. ... He was pitching really well in Spring Training, came back into camp again this year kind of got back on track. You could see he kind of cleaned things up over the winter. He's a guy that's going to perform, and he continues to get better. We think he'll continue to improve. He's got a good little pitch mix. So he's a guy that we think can compete."

With long reliever Paul Campbell's 38 pitches on Saturday, Holloway was the choice to shore up length in the bullpen. He appeared in one game last season after previously not pitching above the Class A Advanced level, and immediately showed why the Marlins turned to him, throwing a pair of perfect innings in Monday night's 4-1 loss to the Cardinals.

Hernandez's next turn in the rotation was slated for the Marlins' road opener on Thursday afternoon against the Mets at Citi Field. Neidert as well as lefties Daniel Castano and Braxton Garrett (No. 9 prospect) are options to fill the spot. The latter two are participating at the alternate training site in Jacksonville, Fla.

"These first couple of games will have some kind of impact on that," Mattingly said. "It depends on how this goes. If it's a night when something would happen to Trevor [Rogers] really early, we probably would hand the ball to Nick and go get him. And that would change Elieser's spot, who would have to pitch then, so we would make different plans than right now. That's kind of semi the plan between him and Paul. See what we do, and where this thing goes."

The 25-year-old Hernandez became the second Marlins pitcher in less than a week to sustain an injury after Miami's relatively healthy spring. An MRI revealed mild inflammation in the right shoulder of Sixto Sánchez last Friday. He experienced the discomfort while building up his pitch count at the alternate training site. Had he not experienced the setback, MLB Pipeline's No. 15 overall prospect would've made his season debut on Sunday in the series finale against the Mets. That means one of Neidert, Castano and Garrett will be needed as the fifth starter in the rotation.

Aside from the injuries to Hernandez and Sánchez, MLB Pipeline's No. 68 prospect Edward Cabrera arrived to camp and was diagnosed with an inflamed nerve in his right biceps. He was expected to have an outside shot at the rotation after nearly making his MLB debut last season. Veteran left-hander Gio González had signed a Minor League deal in the spring, but he retired on March 25. When asked if the organization might look externally for help, Mattingly deferred to general manager Kim Ng and the rest of the front office.

"There's no doubt that I think losing two guys right away challenges your depth," Mattingly said. "And that's really what happens. You have to deal with that. Both guys we feel like are going to get back and be a part of this mix, but for the time being, we're getting challenged, and if that would continue to happen every couple of days the way it seems to have happened, obviously that puts you in a tough spot. I think that would put any team in a tough spot. But right now I would say we really don't want any more. Obviously we don't want to lose another starter in the next few days here."

Worth noting

Marlins players who've yet to be vaccinated and want to receive the COVID-19 vaccine will get their first dose prior to leaving for the club's road trip, which begins on Thursday.

Opening Day starter Sandy Alcantara, who was part of last year's COVID-19 outbreak, will be among the group to do so. As of Monday, all Florida residents 18 years of age and older are eligible to receive a COVID-19 vaccine as prescribed by the Food and Drug Administration.

"I think that's a great opportunity for me, for my family and for baseball, too." Alcantara said during a Zoom call. "I think we got to get it. If you're going to be in the normal life, we have to do it."

Clubs were informed last Monday that MLB and the MLBPA have agreed to relax certain health and safety protocols contained in the 2021 Operations Manual for fully vaccinated Tier 1 Individuals and for clubs where 85% of their Tier 1 Individuals are fully vaccinated. As part of that memo, players and staff were again strongly encouraged to receive one of the approved COVID-19 vaccines when eligible.