WASHINGTON -- Nationals first baseman Adam Dunn said Tuesday there hasn't been any progress on a contract extension, although his agent, Greg Genske, and the club continue to talk.

Dunn is in the last year of a two-year, $20 million contract with the Nationals, and he is looking to get a four-year deal.

"If we can't get something done, obviously, I would like to see what my option are," Dunn said to MLB.com. "I want to stay in one place. It's something I want to do. I never asked for anything like [a four-year deal] ever in my career. It's one thing that I want -- the longer-term contract. That's all I ask for."

Dunn is clearly one of Washington's best hitters, batting .271 with a team-leading 34 home runs and 91 RBIs entering Tuesday's action against the Mets. He also is considered one of the leaders in the clubhouse. Dunn is not afraid to tell a player when he is doing something wrong on the field.

General manager Mike Rizzo declined to talk about the contract negotiations with Dunn.

Wang out for year, preparing for fall ball

WASHINGTON -- Nationals right-hander Chien-Ming Wang will not play a big league game this season because of a weak shoulder, but the veteran is preparing to play in the instructional league for Washington this fall, according to general manager Mike Rizzo.

"We are going to try to get him prepared to go to the instructional league, participate there, get him some innings, and get [him] stretched out," Rizzo said.

Wang, 31, is arbitration-eligible this offseason and Rizzo is hoping that the club can work out a deal with Wang in the offseason. Last spring, Wang signed a one-year deal worth $2 million.

"We don't know what the plan is," Rizzo said. "We are in communication with his agent. We are going to see if we [can] work something out. We like him. We want him. We want to keep him with the club."

While with the Yankees, Wang suffered a torn right shoulder capsule that was repaired in July 2009, but he has been slow to recover from the injury. Rizzo has said that baseball has not had an injury like the one Wang has sustained. NFL quarterback Drew Brees had a similar injury a few years ago, but recovered and guided the New Orleans Saints to a Super Bowl title last February.

Nats boost pitching staff with callups

WASHINGTON -- The Nationals recalled right-hander Yunesky Maya and selected the contract of right-hander Joe Bisenius from Triple-A Syracuse.

Additionally, left-hander Ross Detwiler was recalled from rehab and reinstated from the 15-day disabled list, while catcher Carlos Maldonado was designated for assignment.

Maya, who started in Tuesday's game against the Mets, went 1-1 with a 0.87 ERA (one earned run in 10 1/3 innings) in two starts with the Chiefs. The 28-year-old made five Minor League starts this season, going 1-2 with a 3.38 ERA and a .225 batting average against.

Bisenius, 27, posted a 1-0 record with a 2.70 ERA in 14 relief appearances with the Chiefs in 2010. He went a combined 4-0 with one save and a 3.05 ERA in 34 appearances this season at three levels in the Nationals' system. Bisenius struck out 46 batters with a .210 batting average against in 38 1/3 innings.

A hard-throwing prospect in the Phillies' system during his first six seasons, Bisenius signed with the Nationals as a Minor League free agent on May 10. He saw action in two games with the Phillies in 2007 (pitching two shutout innings), and is 24-20 with 12 saves and a 4.07 ERA in 234 games/16 starts during his Minor League career.

Detwiler, 24, has missed the past 30 games after going on the 15-day disabled list (hip) on Aug. 8, retroactive to Aug. 6. He is 0-2 with a 3.46 ERA in three starts with Washington this season, and is 3-2 with a 2.27 ERA in 10 Minor League outings. Detwiler most likely will be a reliever for the rest of the season.