Both pitchers were available for the Royals' game Wednesday night against the Oakland Athletics.
Kansas City's relief corps has struggled mightily during a 2-5 start, nobody more than left-hander Matt Strahm. He was optioned to Omaha in an attempt to get the young reliever on track.
The Royals also optioned extra outfielder Terrance Gore to Double-A Northwest Arkansas.
Alexander made 17 appearances with the Royals last season and had thrown two scoreless innings at Omaha this season. Junis allowed two runs in 6 1/3 innings in a start for Omaha last week.