The Philadelphia Phillies announced Friday they placed right-hander Aaron Nola on the 15-day injured list with a right ankle sprain.
The move is retroactive to May 15.
Nola said he injured himself doing agility work May 8, according to The Athletic's Charlotte Varnes. His ankle has gotten better but is still swollen.
The 31-year-old has struggled this season, posting a 1-7 record with career-worst marks in ERA (6.16) and FIP (5.03).
He was lit up for nine earned runs on 12 hits Wednesday in a 14-7 loss to the St. Louis Cardinals.
Philadelphia recalled right-hander Daniel Robert from Triple-A Lehigh Valley to fill Nola's spot on the active roster.
The Phillies intend to call up their No. 8 prospect, Mick Abel, to start Sunday in what will be his major-league debut, according to Varnes.
