The No. 5 spot in Cleveland's rotation has been open since Carlos Carrasco was moved to the bullpen Monday, and Tomlin's 20-inning run of scoreless innings at Triple-A was too much for Francona and the front office to ignore.
"Josh's last two outings have been pretty good," Francona said. "We wanted to keep our [other starters] on their day. He pitched so well in Spring Training. He'll help us, I think, to win."
Tomlin threw a three-hit shutout on Thursday for Triple-A Columbus. He struck out 10 batters in that outing. He has not allowed a run in 20 innings, dating back to April 18.
Francona also considered Trevor Bauer and T.J. House for the start.
"There's about three guys [in Triple-A] throwing the ball well, which is nice," Francona said. "You know going through the season, you're going to need guys. Fortunately, that's a nice thing to have."
Stephen Ellsesser is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.