The Cincinnati Reds intend to place right-hander Johnny Cueto on the 15-day disabled list, according to a major league source.
Cueto, who left Saturday night's game at Pittsburgh with one out in the fifth inning, has a strained latissimus dorsi muscle, the source said.
The injury initially was described as a right triceps pain. The latissimus dorsi begins in the lower back and attaches to the underside of the shoulder.
In last season's NLDS against the Giants, Cueto lasted only eight pitches before leaving the game -- and ending his season -- with a pulled muscle in the right side of his lower back.
The loss of Cueto could lead the Reds to promote 23-year-old left-hander Tony Cingrani, who has struck out 26 and walked only two in 14-1/3 innings at Triple-A Louisville this season.
None of the Reds' starters missed a turn last season, when the team won 97 games and the NL Central title.