The move, which is retroactive to May 21, allows Mike Parisi to take Pineiro's start in the rotation and brings up Kelvin Jimenez from Triple-A Memphis. Pineiro acknowledged that heading to the DL was right for him and the organization. He will be eligible to come off the DL on June 5.
"Right now I cannot pitch, so they're going off of that," Pineiro said. "They asked me today if I could pitch and I said 'No.' Not that it hurts, but I can't go out there and be 100 percent."
Pineiro injured his right groin on May 21, a day after his last start. Warming up with the rest of the Cardinals, Pineiro was jogging in the outfield when he felt a tweak in his groin.
The injury comes after a start that Pineiro believed was one of his best of the year. He went 5 2/3 innings and gave up three runs, all of which came on one home run.
"It's the worst timing ever," Pineiro said. "With the sharpness and the stuff I had in that start, you feel good about yourself. ... I feel bad because I'm letting the team down. And I'm a guy that I'll pitch if it hurts a little somewhere, but this, I won't be able to pitch at my best level."
When asked if he could pitch off the mound, it did not take long for Pineiro to say that was not a possibility.
"No chance, not today," Pineiro said. "No, I'm not going to lie to you guys. I can play catch nice and easy, but when I go give it that little extra off the mound, you still feel something slight there."
Manager Tony La Russa had options at his disposal when the team sent Pineiro to the DL. He could have left Parisi in the bullpen and brought up Anthony Reyes from Triple-A, but decided to put Parisi in the rotation.
Parisi, who threw two innings of relief on Tuesday night, is a starter by trade but has pitched out of the bullpen since his recall from Triple-A. He has a 2.87 ERA and 10 strikeouts in 15 2/3 innings with the Cardinals.
After enjoying a good season with Memphis, Jimenez was called up for the second time this year to pitch for the Cardinals. In 20 relief appearances for Memphis, Jimenez has a 1.88 ERA with 14 strikeouts and three walks in 24 innings. However, he has a 7.20 ERA in two years at the Major League level.
"Jimenez has got experience here," La Russa said. "It seemed like a natural fit."
Lee Hurwitz is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.