GLENDALE, Ariz. -- Dodgers backup catcher Dioner Navarro suffered what might be a strained oblique during batting practice Thursday, possibly opening a roster spot for surprise candidate Hector Gimenez.

Navarro, who signed a one-year, $1 million contract this offseason to spell starter Rod Barajas, felt pain in his right side while taking batting practice. He was to start behind the plate in Thursday's game with the Rockies, but instead went for an MRI.

"I don't know what to tell you," Navarro said, as the club awaited the results. "It's the first time for me, so I can't tell you how bad it is. It doesn't seem to be that bad. I felt it on a swing, and as soon as I felt it I shut it down. I didn't want to aggravate it more than it was."

Manager Don Mattingly said he was watching Navarro take batting practice when the injury occurred.

"We've been telling the guys if they feel something, just to stop," said Mattingly. "Sometimes they try again, just hoping it's nothing."

Mattingly replaced Navarro in the lineup with Gimenez, the switch-hitting catcher the club has been trying to find a spot for because of his bat.

Gimenez, who also has been playing first base and the outfield, went 1-for-3 and caught six innings, drawing praise from starting pitcher Hiroki Kuroda.

"He stopped a lot of my split-finger fastballs," said Kuroda. "He made a lot of right calls."

Gimenez is hitting .289 with three homers and seven RBIs this spring, but he's an eight-year Minor League veteran with only two Major League at-bats. Gimenez, once a promising catching prospect with Houston, had his career derailed by 2007 shoulder surgery.

The more experienced catching candidate to replace Navarro would be A.J. Ellis, whose path was blocked by the signings of Barajas and Navarro after the Dodgers non-tendered last year's starter, Russell Martin. Ellis played in 44 games for the Dodgers last year, batting .278.

Taking advantage of the possible opening, Ellis replaced Gimenez and hit the first walk-off home run of his life, a three-run shot in the bottom of the ninth off his former Minor League teammate, Chris Malone.

"It felt good to square one up," said Ellis, who has started only twice this spring and is hitting .138.

Gimenez could get the nod over Ellis because he's a switch-hitter, and because Ellis still has an option left. Gimenez is out of options, and if the club tries to send him down, he could be claimed by another team. Gimenez has caught only 24 innings this spring, compared to 73 2/3 for Ellis.

Navarro is in his second stint with the Dodgers. He was non-tendered in December by the Rays, with whom he was an All-Star in 2008, a year in which he finished with a .295 average. But that plunged to .218 in '09 and .194 in '10, when he was left off the postseason roster and went home.

Navarro has not been on the disabled list since 2008.

If an oblique strain is diagnosed, it would be the second one suffered by the Dodgers this spring. Fifth starter Jon Garland has been out since March 9 with a side strain suffered while pitching, and he is close to returning to the mound.