Montas was hit by a line drive by Taylor Ward and left the game with a bruised right forearm after 16 pitches. Brent Suter allowed four hits in 3 1/3 innings. Emilio Pagan (2-1) earned the win after allowing one hit in two innings.
José Soriano (0-3) did not allow a hit until there was one out in the sixth inning. Elly De La Cruz singled. Nick Martini reached on a error by Luis Rengifo. Christian Encarnacion-Strand doubled and Jeimer Candelario hit a triple to put the Reds up 3-0.
Soriano finished with three unearned runs on three hits in six innings, a career high, and struck out a career-high seven batters.
Alexis Diaz earned his fourth straight save in five tries.
Anthony Rendon placed on injured list
(Carolyn Kaster / Associated Press)
Angels third baseman Anthony Rendon was placed on the 10-day injured list with a strained left hamstring.
The 33-year-old Rendon got hurt running out an infield hit leading off the game against the Reds on Saturday.
Rendon is hitting. 267 with three RBIs this season. He started the season 0 for 19 and has 20 hits since April 5.
An All-Star with Washington in 2019, the third baseman is in the fifth season of a $245 million, seven-year contract. He has not played more than 58 games in any season with the Angels because of a series of injuries.
Rendon played only 43 games last season and had three stints on the injured list. He played in just 47 games in 2022 because of a wrist injury. Rendon had a string of injuries that limited him to 58 games in 2021.
The Angels selected the contract of infielder Ehire Adrianza from Triple-A Salt Lake. Right-hander Robert Stephenson was moved to the 60-day IL to make roster room for Adrianza.