Philadelphia Phillies right-hander Zack Wheeler has been placed on the injured list after a blood clot was discovered in his right upper extremity near his shoulder, according to The Athletic's Charlotte Varnes. Phillies executive Dave Dombrowski told reporters that Wheeler will undergo more testing and that the club currently has no available timetable on when he may return.

The Phillies have not yet announced a corresponding move, though it stands to reason they could replace Wheeler by activating fellow right-handed starter Aaron Nola ahead of his scheduled start on Sunday.

Wheeler, 35, pitched on Friday night against the Washington Nationals. He surrendered two runs on four hits and two walks over five innings of work. Wheeler punched out six of the 20 batters he faced. Through 24 starts to date this season, he's amassed a 2.71 ERA (166 ERA+) and a 5.91 strikeout-to-walk ratio. His contributions have been worth an estimated 5.3 Wins Above Replacement, per the estimates housed at Baseball Reference.

The Phillies only just announced plans to use a six-pitcher rotation upon Nola's return from a three-month absence caused by a sprained ankle. The rest of the Phillies rotation includes Taijuan Walker, Ranger Suárez, Cristopher Sánchez, and Jesús Luzardo. Nola had started nine times before being deactivated. In those appearances, he compiled a 6.16 ERA (73 ERA+) and a 3.25 strikeout-to-walk ratio in 49 innings. It's fair to write those marks are far worse than Nola's usual.

The Phillies suffered a 2-0 loss on Saturday, dropping them to 70-53 on the year. They now hold a five-game lead in the NL East after the New York Mets' win over the Seattle Mariners.