Ayala went 5-5 with a 2.64 ERA and a save in 66 relief appearances for Baltimore last season.
The 34-year-old right-hander has a career 36-46 record with a 3.35 earned run average and 19 saves over 495 appearances between the Montreal Expos/Washington Nationals, New York Mets, Minnesota Twins, Florida Marlins, New York Yankees and Orioles.
He will make $1 million next season.
Reynolds hit .221 with 26 doubles, 23 home runs and 69 RBI over 135 games for the Orioles last season.
He has surpassed 20 homers over the last five seasons, but has also struck out at least 159 times a year during that span. He was due $11 million in 2013.
Baltimore also selected the contract of pitcher Zach Clark on Wednesday.
Clark went 15-7 with a 2.79 ERA in 28 games (26 starts) between Double-A Bowie and Triple-A Norfolk last season.