DENVER -- Rockies left-hander Jorge De La Rosa was placed on the 15-day disabled list Wednesday with a left groin strain, which should give him time to recover and unlock the mystery that has led to a 10.18 ERA through five starts. Colorado recalled righty Eddie Butler from Triple-A Albuquerque to fill his roster spot.
De La Rosa gave up four runs in three innings of Tuesday night's 9-4 loss to the Pirates, and he was pulled when he limped to first after hitting a ground ball in the third inning. He said Wednesday that the issue has existed since his first start, and he has been receiving massage treatments. Yet, he declined to link the groin issue to the poor performances or significantly lower fastball velocity this season.
"It's not the groin, it's me," De La Rosa said.
Rockies manager Walt Weiss said he doesn't believe De La Rosa (1-3) will need more than the minimum DL stint before he's healthy enough to pitch. Weiss believes that whatever healing De La Rosa has to do will be mental as well as physical.
"It probably doesn't hurt -- sometimes you need a mental break, too," Weiss said. "Maybe it's a blessing in disguise."
De La Rosa said the groin is "tight and sore." His leg also didn't look stable when he attempted to run out a ground ball during his previous stint at Cincinnati, when he pitched just two innings and was pulled for ineffectiveness. But De La Rosa said the groin wasn't a huge issue then.
So it's not clear what the main cause is for De La Rosa's struggles this season. This much is known: his 90.1 mph average fastball is the lowest since he averaged 90.4 during three late-season starts after returning from Tommy John surgery in 2012 (he was at 91.4 last year). And De La Rosa, who owns club records for wins (79), strikeouts (905) and home winning percentage (.731), hasn't shown he can pitch with lower fastball speed.
Yet, Weiss noted, "Everything checks out fine with the arm."
De La Rosa offered, "I just feel like my arm is lazy. I've been working really hard to get it stronger every day. But I don't know. I'll rest a little bit just to make it stronger."
Thomas Harding has covered the Rockies since 2000, and for MLB.com since 2002. Follow him on Twitter @harding_at_mlb, listen to podcasts and like his Facebook page. This story was not subject to the approval of Major League Baseball or its clubs.