Singer is on the Royals' taxi squad and is expected to start Sunday against the Twins, Lynn Worthy of The Kansas City Star reports.
Singer was sent down after starting in the second game of Tuesday's doubleheader, but he'll pitch on normal rest during Sunday's series finale at home against the Twins. The 25-year-old began the season in a relief role but allowed four hits and no walks while striking out nine in seven innings during Tuesday's start against the White Sox.