WASHINGTON -- Left fielder Michael Morse was able to hit in the indoor batting cage without any problems on Tuesday. He said he will hit and throw every other day.

Morse, who is on the disabled list because of a torn left lat, is hoping to play his first Major League game of the season on June 8, when the Nationals play the Red Sox at Fenway Park. He would serve as the designated hitter in the American League park.

Meanwhile, infielder/outfielder Mark DeRosa, who is on the disabled list because of a left oblique strain, is expected to start throwing on flat ground on Wednesday. He hopes to start hitting by the end of the week.

"I'm starting to get to the point of being pain free. Now we just have to ramp it up and get a bat in my hand. I feel good," DeRosa said.

Maldonado joins Nats as Leon hits DL

WASHINGTON -- The Nationals placed catcher Sandy Leon on the 15-day disabled list with a high right ankle sprain and selected the contract of catcher Carlos Maldonado from Triple-A Syracuse on Tuesday.

To make room for Maldonado on the 40-man roster, the team also transferred catcher Wilson Ramos to the 60-day disabled list.

This is Maldonado's second Major League stint with the Nationals -- the first coming in 2010. He joins the team a day after Leon was injured in a home-plate collision against the Padres.

It marked the second injury by a Nationals catcher in the last three days. On Saturday, Ramos tore his ACL while going after a passed ball against the Reds. He is expected to be out for the season.

Maldonado, 33, was on his way to Columbus, Ohio, around 11 p.m. ET when he received word that he was promoted to the big leagues. At first, he thought his teammates were pulling a prank on him. But soon thereafter, one of his teammates showed him the video of Leon getting hurt. Maldonado then boarded a plane from Columbus at 7:30 a.m. on Tuesday and flew to Washington.

"It's crazy, what's going on. My teammates [in Syracuse] were making fun of me, [telling me to leave] the catching gear all the time to make sure I don't get hurt," Maldonado joked.

But Maldonado was serious when he talked about Leon and Ramos. All three are from Venezuela, and he was shocked to learned about the injuries they suffered.

"They are from Venezuela, and I played winter ball with Sandy," Maldonado said. "We talk a lot. It's sad what happened to them. I'm excited to get called up, but in the meantime, it's sad, because it was the first time Sandy was here. It was the first game he played [in the big leagues], and I feel bad for him."

Maldonado, who will wear No. 49, was hitting .211 with two home runs and six RBIs in 21 contests this season with Syracuse.

Nats says Rendon could return in September

WASHINGTON -- The Houston Chronicle quoted Nationals third baseman Anthony Rendon saying that he is probably out for the rest of the season because of a badly sprained left ankle, but a team source told MLB.com that was not the case.

The team is hoping that Rendon can be back on the field by September. Rendon, who was playing for Class A Potomac, suffered a badly sprained left ankle while running the bases in a 7-2 loss to Lynchburg on April 7.

Rendon hurt the ankle in the fourth inning after trying to score from second on a bloop single to center by Justin Bloxom. The Nationals' No. 2 prospect went down with the ankle injury after rounding third base.

Rendon has had a history of injuries, including shoulder and ankle problems. However, that didn't stop the Nationals from making him their top pick in the 2011 First-Year Player Draft.

Nats TV voice Carpenter to work FOX game

WASHINGTON -- Nationals TV broadcaster Bob Carpenter will be doing the play-by-play for the Nationals-Orioles game for FOX this Saturday at Nationals Park. His partner in the booth will be former Major Leaguer Billy Ripken.

Carpenter, who has been the TV play-by-play voice of the Nationals since 2006, will also do the Nationals-Orioles game on June 23 for FOX when the teams play at Camden Yards.