Chafin, 31, is having a stellar season.
Chafin, though, has struggled recently, failing to record an out while giving up three runs on two hits and two walks in his last outing, on Saturday, against the Arizona Diamondbacks.
Deichmann, a 26-year-old outfielder, was hitting .300 with four home runs and 34 RBIs for Las Vegas this season, his first in Triple-A.