The Guardians recalled Aleman from Triple-A Columbus on Friday, Francys Romero of BeisbolFR.com reports.
Aleman has gotten off to a dominant start at Columbus this season, allowing just one unearned run with an 18:4 K:BB over 12 innings of relief. The 25-year-old will operate in middle relief and will be making his major-league debut when he gets into a game.