Leiter was optioned to Triple-A Iowa on Saturday, Tim Stebbins of NBC Sports Chicago reports.
EDGE Analysis
Leiter was called up by the Cubs on June 21 but wasn't particularly sharp during his stint with the major-league club. He posted a 4.64 ERA and 1.17 WHIP in 21.1 innings over seven outings during his time in the big leagues and will head back to the minors as part of a move after Steven Brault's contract was selected Saturday.