Left-hander Adam Morgan will likely miss the start of next season after undergoing elbow surgery, giving the Phillies another vacancy to fill this winter as they rebuild a bullpen that was baseball’s worst in 90 years.

Morgan, the Phillies announced, had left elbow flexor tendon repair surgery on Thursday and is expected to miss six to nine months. The 2021 season is scheduled to begin in a little less than six months, April 1 at Citizens Bank Park.

The 30-year-old Morgan is arbitration-eligible for one more season after earning $1.575 million in 2020. He had a 5.54 ERA this season in 17 games and struck out 16 batters in 13 innings. His velocity dipped at the end of the season.

In 2019, Morgan missed a month with a strained forearm and missed the final two months of the season with a strained flexor tendon.

The Phillies will likely enter 2021 with an almost completely revamped bullpen after the unit finished the season with a 7.06 ERA. Tommy Hunter, Brandon Workman, David Robertson, Jose Alvarez, and Blake Parker are free agents. Heath Hembree and David Hale are arbitration-eligible, and David Phelps has a team option worth $4.5 million.

Of those pitchers, only Alvarez -- if healthy -- seems likely to return in 2021. The left-hander was one of the team’s most reliable relievers in the last two seasons but missed the final five weeks of 2020 with a testicular contusion. JoJo Romero and Connor Brogdon both pitched well as rookies and should have roles in 2021. Hector Neris will be arbitration-eligible for one more season if the Phillies decline his $7 million club option.

That leaves four or five spots to fill in the bullpen. Former Phillies general manager Matt Klentak did little last winter to address his bullpen, a decision that played a big role in the team missing the playoffs for a ninth straight year and Klentak being reassigned. Interim GM Ned Rice, who was Klentak’s top assistant, will have little choice but to address it before next season. And now he has one more spot to fill.