Cardinals righty Trevor Rosenthal will open the season on the DL, Jenifer Langosch of MLB.com reports (Twitter links). Sam Tuivailala will take his place on the active roster. St. Louis has three other righties heading to the DL as well: Alex Reyes (who’ll miss the year after Tommy John surgery), John Gant and Tyler Lyons. A lat issue had slowed Rosenthal earlier in camp, but he had seemed on track to start the year back in the bullpen. Though he had been working to stretch out as a starter, the club did not seem to have a rotation spot open — and Rosenthal’s delay apparently nixed that idea. It seems that the lat injury is to blame, Derrick Goold of the St. Louis Post-Dispatch notes on Twitter, though it’s not apparent whether there was any kind of setback. Rosenthal had been able to throw ten spring frames, allowing two earned runs on ten hits while compiling 11 strikeouts against five walks.