Reynolds, 29, batted .221/.335/.429 with 23 home runs and 69 RBI in 135 games for the Orioles last season. In two years with Baltimore, he hit .221/.328/.458 with 60 home runs and 155 RBI in 290 games. Reynolds has hit 20 or more home runs in each of the last five seasons.
Quintanilla, 31, batted .232/.284/.354 with three home runs and 12 RBI in 36 games for the Orioles after being acquired from the New York Mets on July 20.
Pomeranz, 27, was designated for assignment earlier in the day.
With these moves, the Orioles now have 38 players on the 40-man roster.