BOSTON -- The Red Sox had already braced for starting the season without ace Eduardo Rodriguez, who reported to camp two weeks late after testing positive for COVID-19.

Now, however, it looks like he could miss a significant portion of the 60-game season.

The lefty has experienced a setback in his recovery from the virus -- significant enough that the Red Sox are having him stop baseball activities for the time being.

“As with all our players who have tested positive for COVID, we have continued to monitor them with our medical staff,” said Red Sox manager Ron Roenicke. “In Eddie’s case, they have discovered some minor complications with him. But because of it, we’re taking everything very seriously with this matter and we’re going to shut Eddie down from baseball activities for a period of time.”

For a Red Sox team that has a notably thin starting rotation, the latest development with Rodriguez could hamper Boston’s postseason hopes. The Sox will start the season with just three set starters in Nathan Eovaldi, Martín Pérez and Ryan Weber. They will use an opener for one spot and a spot starter for the fifth opening in the rotation.

Are the Red Sox confident that Rodriguez will pitch this season?

“Yes, I am,” Roenicke said. “I think everybody is. We’re always hopeful. There can be things that come up because this is a virus that really we don’t know all about, so everything we do is really new in trying to figure out what the right things are to do, especially for our players.”

Though the Red Sox didn’t reveal the specifics of the setback, Roenicke said it is not uncommon in people recovering from COVID-19.

“It has come up with other people that do have this," Roenicke said. "We're really hopeful that this is going to clear up in a short time.”

The Red Sox will reevaluate Rodriguez in a week. In Summer Camp, he threw two bullpens at a low volume of pitches.

“It’s a mild case, but it’s still serious enough to where we feel like, to do the right thing with our players and to take care of them, this is a decision our doctors and [chief baseball officer] Chaim [Bloom] and his crew and all of us have come up with,” Roenicke said. “So, obviously, it backs him off from being active and on the field and being able to be part of our staff. It’s disappointing to him, obviously. He came in here after going through the sickness and felt like he was going to be a full-go -- and now a setback.”

Roenicke said that Rodriguez -- who broke out with 19 wins last season -- didn’t test positive again.

“And actually he feels OK,” Roenicke said. “It’s just during the process of going through the different things these guys go through with the COVID -- and this is from MLB but also from our doctors, what they think is necessary for a player to come back and be healthy and strong and be back on the field -- through that monitoring of what is going on with them, they just discovered we need to make sure we get rid of this completely before we have him back on the field.”