Moustakas is not in the lineup Monday against the Rays, Marc Topkin of the Tampa Bay Times reports.
Moustakas will head to the bench as Cheslor Cuthbert gets the start at third base in his stead. Although he hasn't connected on a long ball yet in April, Moustakas is leading the Royals with seven homers this year, putting him in position to make a run at surpassing his career high of 22 homers, set back in 2015.