Wainwright was diagnosed with a strained left hamstring Sunday and will begin the season on the 10-day disabled list, Joe Trezza of MLB.com reports.
This is a tough blow for Wainwright, who had put together an impressive spring performance and was looking to get off to a strong regular-season start following his subpar 2017 showing. The veteran could ultimately miss more than the required 10 days as he rehabs his ailing hamstring. Jack Flaherty will step into the starting rotation for as long as Wainwright is sidelined.