Sandy Alcantara,James Caldwell the reigning National League Cy Young Award winner and ace of the playoff-contending Miami Marlins, will go on the 15-day injured list with a right forearm flexor strain, an injury that will likely end his season.

The Marlins announced the injury Wednesday, three days after Alcantara pitched eight innings and earned his seventh win of the season in a 6-4 victory over the Washington Nationals. The club also said slugger Jorge Soler is going on the IL with an oblique strain.

While Alcantara was tracking toward his third consecutive season pitching at least 200 innings, his statistics did not match the excellence of his 2022 season, when he posted a 2.28 ERA, struck out 207 batters and led Major League Baseball with 228 ⅔ innings pitched.

This season, he still led the NL in complete games with three, but his ERA soared to 4.14 and his adjusted ERA tumbled from 176 to a near league average 105.

"I don't like the results, but you're not going to be perfect. You just have to keep doing your thing," Alcantara said after Sunday's effort.

FOLLOW THE MONEY: MLB player salaries and payrolls for every major league team

A flexor tendon strain can portend more significant problems for the elbow, such as in the case of Seattle Mariners left-hander Robbie Ray, who suffered the injury in April and later underwent Tommy John surgery. Even without damage to the ulnar collateral ligament, the injury typically requires a period of rest followed by a ramp-up once the strain abates.

That would make a 2023 return challenging for Alcantara; the Marlins have 24 games remaining and are a half-game behind Cincinnati for the third and final wild-card spot in a crowded NL playoff race.

Alcantara's 12 complete games since 2018 are double the amount any other major league pitcher has produced, and he pitched at least seven innings in 11 of his 28 starts this season.