WASHINGTON -- With Adam LaRoche ailing because of right oblique soreness, Chad Tracy, not Tyler Moore, will get most of the playing time at first base.

Nationals manager Davey Johnson is hoping that LaRoche doesn't go on the disabled list. If he does, LaRoche would be the eighth Nationals player to be put on the DL since April 3.

"Boy, we have had a rash of [injuries], starting with [Michael] Morse," Johnson said. "It's working its way through the club. I hope it's not contagious. I'll probably get it."

As for Moore, he isn't going to start, because Johnson wants to give his veterans like Tracy and Xavier Nady playing time.

"I like the heck out of Tyler Moore," Johnson said. "He can flat-out hit, but he is a rookie. [LaRoche] is going to be out a few days. This is not the time to try and break a young phenom in to a position where [the other guy] will be back soon."

Once Ryan Zimmerman is activated from the disabled list, Moore will more than likely be sent back to Triple-A Syracuse.

Moore, ranked No. 14 by MLB.com among Washington's prospects, was hitting .286 with seven home runs and 20 RBIs before getting recalled to the big leagues. In his first two big league games, Moore was 1-for-4.

In the two years prior to this season, Moore hit a combined 60 home runs with 201 RBIs for Class A Potomac and Double-A Harrisburg.

Zimmerman feels good hitting off tee

WASHINGTON -- Nationals third baseman Ryan Zimmerman, who is on the disabled list because of an inflamed right shoulder, took swings off a batting tee without any pain on Friday. According to manager Davey Johnson, Zimmerman swung the bat at 75 percent.

"He had no discomfort. He felt good about it," Johnson said about Zimmerman.

On Saturday, Zimmerman is expected to take batting practice, and he is still shooting to play against the Pirates on Tuesday. Johnson also left it open that Zimmerman could play against the Phillies on Sunday.

"I'll check with the medical staff, but, knowing Zim, he will probably want to play," Johnson said. "We are scheduled for Tuesday. I would not be averse to Sunday."

Zimmerman will avoid playing in a rehab assignment.

"We are not going to waste those bullets," Johnson said.

Zimmerman has played in 15 games this season, and is 13-for-58 (.224) with a home run and seven RBIs.