KANSAS CITY - The Orioles designated outfielder Nolan Reimold for assignment today, one of their four roster moves before their series opener against the Royals.

Shortstop J.J. Hardy was placed on the 15-day disabled list with a left groin strain. The Orioles activated Steve Pearce from the disabled list and recalled reliever Jorge Rondon from Triple-A Norfolk.

Reimold, 31, appeared in 39 games for the Orioles this season and batted .227 (22-for-97) with three doubles, one triple, two home runs and eight RBIs. He signed a minor league deal in February and had his contract purchased on June 9.

Hardy has committed only three errors in 93 games this season, compiling a .992 fielding percentage, but he's batting .222/.253/.315 and hasn't homered since July 29. He felt discomfort in his groin Friday night and aggravated the injury late in yesterday's game.

Pearce, 32, was on the 15-day disabled list with a left oblique strain retroactive to July 19. He went 3-for-12 with two doubles, a walk, a run scored and a hit by pitch in four rehab games - two in the Gulf Coast League and two at Double-A Bowie.

In 58 games with the Orioles, Pearce is batting .227/.290/.392 with six doubles, one triple, seven home runs and 24 RBIs.

Rondon, 27, has gone 3-1 with a 2.42 ERA in 29 relief appearances with Triple-A Norfolk this season. He's posted a 2.30 ERA in 34 combined appearances between Norfolk and Triple-A Albuquerque of the Rockies organization.

Rondon made one relief appearance with the Orioles on Aug. 2 and threw 3 1/3 scoreless innings against the Tigers.

The Orioles are going with an eight-man bullpen and three-man bench. They have 37 players on their 40-man roster.

Here's the Royals lineup for tonight's game:

Alcides Escobar SS
Ben Zobrist LF
Lorenzo Cain CF
Eric Hosmer 1B
Kendrys Morales DH
Mike Moustakas 3B
Salvador Perez C
Alex Rios RF
Omar Infante 2B

Kris Medlen RHP