WASHINGTON -- A three-game sweep at the hands of the Yankees stymied some of the momentum the Nationals had gathered in June, but the number of players returning from injuries remains a source of optimism.

Jayson Werth has been out since breaking his left wrist on May 6, but manager Davey Johnson said the veteran right fielder believes he's "about a month away" from returning. The severity of the injury forced doctors to insert a metal plate into the wrist. According to Johnson, Werth's return could come in late July at best, though doctors will X-ray the wrist again in a couple of weeks.

"The doctors saw him Friday or Saturday and said the wrist was knitting very well," Johnson said. "He's probably not going to be able to do anything until a pretty good ways after the All-Star break. The injury was so severe with that plate in there, it's going to have to be fully healed before he's doing any baseball stuff."

In 27 games before the injury, Werth was batting .276 with three home runs and 12 RBIs in 113 plate appearances.

Meanwhile, utility man Mark DeRosa is back after the death of his father, Jack, following a prolonged battle with cancer. DeRosa also has been on the disabled list since April 29 with a strained left oblique. Johnson said DeRosa looked good working out and running with the team before Tuesday night's game, and since DeRosa hasn't batted in about five weeks, he will probably head to Class A Potomac for a rehab assignment.

"The good news is the MASH troops are coming around," Johnson said.

Other Nationals injury updates:

• Infielder Chad Tracy, out since May 26 due to a right adductor strain, was back in the clubhouse on Tuesday. Johnson said Tracy is recovering better than expected and could return shortly after the All-Star break.

• Closer Drew Storen threw a bullpen session on the team's off-day Monday and is expected to return around the All-Star break. Storen had surgery to remove bone chips from his elbow on April 11.

• Reliever Henry Rodriguez, on the disabled list since June 7 with a strained right index finger, could return "inside a week, depending on how things go," Johnson said. Rodriguez began a rehab assignment with Triple-A Syracuse on Tuesday.

• Reliever Cole Kimball also began a rehab assignment with the GCL Nationals on Tuesday, pitching one scoreless inning.

Johnson: Morse, Zimmerman will get on track

WASHINGTON -- Nationals manager Davey Johnson knows that Michael Morse and Ryan Zimmerman are struggling. But the skipper made one thing clear before Tuesday's game -- he still believes in them.

In fact, Johnson kept Zimmerman batting third and had Morse in the cleanup spot for Tuesday's series opener with the Rays. Johnson's also spoken with both to reassure the two since he feels they may be pressing a bit.

"I think they're both really good hitters," Johnson said. "[Sometimes] you try to do more. And sometimes more is not better, less is better."

Zimmerman (.229) and Morse (.211) both have battled injury problems. The third baseman (right shoulder inflammation) was on the 15-day disabled list starting in late April, and Johnson said he doesn't believe the injury is still bothering Zimmerman.

In addition, Zimmerman (three homers, 22 RBIs) said he's not going completely rework his swing. He'll just battle to get through the dry spell.

"I'll continue to work and do the stuff I've done my whole career," Zimmerman said. "You tinker with the little things here and there. Baseball is one of those sports where you struggle and then you get a swinging bunt and go 25-for-50. Hopefully that'll happen soon."

Morse missed the first 50 games with a lat strain. He came back June 1 and also experienced trouble at the plate, with no homers and four RBIs in his first 14 games.

The outfielder was so concerned about his own performance that he came to Johnson after Sunday's loss to the Yankees and asked to be moved down in the lineup since he was "killing" the team. Johnson waved him off.

"I [said], 'I'm not worried so I don't want you to worry,'" Johnson said. "Basically the same [thing] ... with Zim. I know the ability's there. I'm not worried."

In Tuesday's 5-4 loss, Morse hit his first home run of the season, a two-run shot off Rays starter David Price. Zimmerman went 1-for-4 with a run scored.

"I thought [Morse] swung the bat good, and I thought Zim swung the bat good," Johnson said.

-- Jeff Seidel

Worth noting

• The Nationals and Braves rescheduled the rained-out June 1 game for July 21 as the first part of a day-night doubleheader. Game 1 is set for a 1:05 p.m. ET start, with the nightcap at 7:05, or later depending on when the opener finishes.

• With his single in the sixth inning of Tuesday night's game, Ryan Zimmerman is six hits away from 1,000.

• The Nationals have five games left in a stretch against East teams. They will have played 32 straight games against either the AL East or the NL East. After this series with the Rays, that stretch will conclude with three games in Baltimore this weekend.