Faulker, 24, was on the Rangers' Opening Day roster but was sent down after posting an 8.31 ERA in five appearances. He returned for three appearances in May and was sent down again after allowing three runs (one earned) in 1 1/3 innings. He pitched one scoreless inning in his only September appearance.
Faulkner was 5-3 with a 3.97 ERA in 41 games at Triple-A Round Rock. He averaged 7.7 hits, 4.0 walks and 7.7 strikeouts per nine innings.
McCain, 25, was a non-drafted free agent out of Troy University in 2014 who went 7-4 with a 3.39 ERA in 41 relief appearances at Class A Advanced High Desert. In 74 1/3 innings, he allowed 64 hits and 25 walks while striking out 75.
McCain has a chance to be a late-developing prospect for the Rangers. His college career was derailed by labrum surgery that forced him to miss the entire 2012 season.
T.R. Sullivan has covered the Rangers since 1989, and for MLB.com since 2006. Follow him on Twitter @Sullivan_Ranger and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.