WASHINGTON -- Nationals outfielder Corey Brown is most likely out for the season because of staph infection in his right knee.

The team doctors felt they needed to open up his knee to get rid of the infection.

"The knee wasn't progressing like it should," Johnson said. "The orthopedic surgeon said they were going to have to open [the knee up] a little bit to get the infection out. So he will not be joining us on this trip [to New York."

Johnson found out about Brown's problems on Sunday, when the Nationals were packing their bags for a four-game series against the Mets that began Monday. The team doctors then suggested to Johnson that Brown would be better off if he didn't travel.

Since his promotion to the big leagues last Tuesday, Brown has been hitless in three at-bats for Washington.

Johnson gives Zimmerman's glove high praise

NEW YORK -- Nationals manager Davey Johnson played with Orioles third baseman Brooks Robinson for eight seasons, and the skipper said third baseman Ryan Zimmerman is up there with Robinson in terms of playing great defense at the position.

In the eighth inning of Monday night's game against the Mets, for example, Zimmerman dove for a ground ball hit off the bat of Justin Turner. On his right knee, Zimmerman was able to throw out Turner for the second out in the inning.

"I've never seen a third baseman with quickness that he has, with the catch and quick release that he has," Johnson said about Zimmerman. "A lot of times, I've seen more balls hit off Brooks' chest and the balls just seem to die right there or they just stayed on his chest, [and he would] pick the ball up and throw the guy out. With Zim, he just about gets the glove on the ball just about every time. He has tremendous hand-eye coordination and a lot of range."

Worth noting

• Nationals right-hander Garrett Mock was outrighted to Triple-A Syracuse on Tuesday, a week after he was designated for assignment. Mock was a combined 1-5 with a 6.39 ERA with Gulf Coast Nationals, Class A Potomac, Double-A Harrisburg and Syracuse.

• Nationals TV play-by-play broadcaster Bob Carpenter was under the weather on Tuesday and took the day off. Radio play-by-play broadcaster Dave Jageler transferred over to the Mid-Atlantic Sports Network for the day. Carpenter is expected to be back on the air on Wednesday.