Team officials said Friday that the 30-year-old sent to the minors this week will miss three to four months.
Tomlin felt discomfort in his throwing shoulder after a minor league start on Monday. He spent spring training competing for a spot in the Indians rotation but was optioned to Triple-A Columbus on Sunday.
Tomlin pitched in 25 games for the Indians last season, posting a 6-9 record and 4.76 ERA. Tomlin missed most of 2013 after having Tommy John surgery in August 2012.