Lucas Giolito went from being the Boston Red Sox's presumed Opening Day starter to possibly missing the season due to an elbow injury, according to ESPN's Jeff Passan.

ESPN reported Tuesday that the right-handed pitcher could miss the entire 2024 season after he underwent a test that showed he has a partially torn ulnar collateral ligament and flexor strain.

More than likely, Giolito will need surgery to correct the injuries, which would keep him out for the season, as the anticipated recovery time is around six months.

Giolito finished with a 4.88 ERA and 204 strikeouts in 184 1/3 innings and 33 starts in 2023. He played for the Chicago White Sox, Los Angeles Angels and Cleveland Guardians last season.

Boston signed Giolito to a two-year, $38.5 million contract this winter. Losing Giolito would be a massive blow for a Red Sox team that didn't do much else in free agency and has very little contingency plan if the 29-year-old isn't available.

Left-handed pitcher Chris Sale was traded in the offseason. The Red Sox also signed reliever Liam Hendriks, who underwent Tommy John surgery, and righty Cooper Criswell to help fill out the bullpen.

Last season, Boston finished 78-84 and in last in the American League East. It was the second year in a row the Red Sox have finished last in the division.