SAN DIEGO -- Nationals third baseman Ryan Zimmerman missed his second straight game on Tuesday due to a sore left shoulder, but it's feeling much better than it did Monday.

In fact, Washington manager Manny Acta went so far as to say Zimmerman was available during Tuesday's game against the Padres, but it was doubtful he would see action. Zimmerman is listed as day-to-day, and neither the team nor Zimmerman announced when he will be back in the lineup.

"I probably could swing if I wanted to, but there is no reason to rush it," Zimmerman said. "I'm going to rest and relax today. [I'll] keep doing the treatments that have been working.

"It feels significantly better than it did yesterday, so I think that is a good sign. ... We'll give it a couple of days here, and hopefully everything will go away, so we don't have to get an MRI. So far, so good."

Zimmerman had been playing more than a week with the sore shoulder. He hurt it on May 18, when he was sliding headfirst into second base against the Orioles. The news was first reported on Saturday by catcher Paul Lo Duca, who made a guest appearance on the Mid-Atlantic Sports Network.

Zimmerman is not used to sitting out for significant periods of time, and he acknowledged he has a different perspective from the bench.

"It's very boring. I don't know what to do," Zimmerman joked. "It's definitely a different perspective. You look and see a lot of different things that you don't really see when you are playing."

This is Zimmerman's second injury in less than a year. He broke his left hamate bone during the offseason, but he recovered quickly and didn't miss any Spring Training action.

With Zimmerman out on Tuesday, Aaron Boone received the start against the Padres.