Baseball America correspondent Evan Grant reports that righthander Michael Main has a stress fracture in his right rib cage that will prevent him from pitching until at least late May.

Main was the No. 24 overall pick in last year’s draft and the No. 6 prospect in the Rangers organization. He struck out 34 batters in 28 innings split between the Rookie-level Arizona League and short-season Spokane in his professional debut.