The Red Sox shut down Rodriguez due to complications related to his COVID-19 diagnosis. The team later revealed that he developed a heart condition (myocarditis) from contracting the virus, which he is still dealing with.
"It has not resolved, it is still there," Chaim Bloom, Red Sox chief baseball officer, said. "While we remain optimistic he will make a full recovery, due to the fact that it is persistent and the amount of care we need to take with this, he's not going to be able to come back and pitch this year."
Rodriguez was poised to open the season as the ace of a depleted Red Sox staff after they traded David Price to the Los Angeles Dodgers, and Chris Sale underwent Tommy John surgery.
The Red Sox pitching staff has accrued a 5.32 ERA in 71 innings so far this season.