"It was just trying to do what we think is best to help the baseball team," Ausmus said.
The move will set the Tigers up for a five-man rotation moving forward into the All-Star break. The off-day Monday allowed Ausmus to start Jordan Zimmermann and Michael Fulmer in the first two games of a four-game series against the Rays beginning Thursday.
Sanchez was available out of the bullpen Tuesday as the Tigers began a brief two-game series with the Marlins at Comerica Park to wrap up a nine-game homestand.
Sanchez was 3-7 with a 6.71 ERA in 12 starts. He went 0-4 with a 7.09 ERA in six starts in May before he was moved to the relief role.
He has gone 1-1 with a 1.86 ERA in six appearances out of the 'pen, allowing two runs over 9 2/3 innings.
Right fielder Steven Moya was out of the Tigers' lineup on Tuesday in favor of Mike Aviles. Ausmus said he made the decision because of the matchup against Miami's left-handed starter Adam Conley.
Kyle Beery is a reporter for MLB.com based in Detroit. This story was not subject to the approval of Major League Baseball or its clubs.