(Evan Vucci/AP)

“At this point, as far as I know, it’s not real favorable,” Manager Davey Johnson said. “It looks like he’s going to need to some more rest. We’ll just have to wait and see.”

The Nationals planned to wait at least until Wednesday to make any roster moves. If Zimmerman lands on the disabled list, Johnson said he would use Mark DeRosa, Chad Tracy and Steve Lombardozzi to replace Zimmerman at third base.

If Zimmerman goes on the disabled list, the Nationals would have several options in Class AAA Syracuse to replace his spot on the roster. Tuesday afternoon, Brett Carroll, who opened the season in the majors with the Nationals before they designated him for assignment to make room for Rick Ankiel, cleared waivers and accepted the assignment. Jason Michaels and Mark Teahen both have ample major league experience. Tyler Moore, 25, is on the 40-man roster and has smashed six homers in 17 career games at Class AAA.

Zimmerman had expected to play Tuesday as the Nationals opened a six-game West Coast road trip, but he still felt pain in his shoulder when he made contact while taking batting practice. The Nationals originally thought Zimmerman had inflammation, but after an x-ray they learned he had either a strained or sprained AC joint. Zimmerman said he felt “100 percent” when he threw and was confident his shoulder had no structural damage.