Nationals option John Lannan

WASHINGTON -- John Lannan's salary is $5 million, and he started on Opening Day for the Washington Nationals in 2009 and 2010. This season, the left-hander will be at Triple-A Syracuse for Game 1.

In a completely unexpected move, the Nationals optioned Lannan to the minors and shifted lefty Ross Detwiler from the bullpen to the starting rotation. The decision was announced after Washington's 8-7 loss to the Boston Red Sox on Tuesday, two days before the Nationals begin their season at the Chicago Cubs.

"I came to terms with going to the bullpen and being the long guy and waiting for an opportunity," said Detwiler, the No. 6 overall pick in the 2007 amateur draft, "and it came up a whole lot quicker than I thought it would."

While Detwiler spent much of 2011 at Syracuse, Lannan was making a staff-leading 33 starts for the Nationals, going 10-13 with a 3.70 ERA over 184 2/3 innings. Lannan appeared to have a spot in this year's rotation locked up after Chien-Ming Wang was injured during spring training, but Nationals manager Davey Johnson said the team wants to see "how good 'Det' can be."

"I had a change of heart," Johnson explained of the sudden change. "The best thing for the organization today, as well as tomorrow, is for Ross Detwiler to get the opportunity to start."

Detwiler is 6-14 with a 4.07 ERA in 39 appearances with the Nationals, including 29 starts. While he's grown used to working in relief, Johnson said Lannan is not.

"It wouldn't have been a good fit for him in the bullpen. I know he doesn't like it out there," Johnson said, noting Lannan would be the Opening Day starter at Syracuse.

The Nationals must figure Lannan will help them in some way this season, because they would have been responsible for only a fraction of his 2012 salary if they had waived him by Monday.

How out of the blue was this? Detwiler said he didn't have any inkling right up until the moment he stepped back into the dugout after pitching one inning in relief -- a 1-2-3 sixth -- against Boston on Tuesday.

After Detwiler exited the game, he recalled, "Davey told me it was just kind of a tuneup for my next start. And I kind of gave him a look like, 'What are you talking about?' And that's how I found out."

Added Detwiler: "Johnny's a good friend. You never want to see a good friend leave the clubhouse. ... It's kind of bittersweet seeing Lannan go. But I also get a chance to start now."

Johnson said he expects Wang to miss three or four starts.

Because Detwiler's bullpen spot was not filled by Lannan, right-handed relievers Ryan Mattheus and Craig Stammen both made the team.

Stammen and Detwiler, slated to earn $485,000 this season, lived together while at Syracuse in 2011.

"I feel great for him. He's definitely deserved it," Stammen said. "It's unfortunate that John has to suffer from that, but that's the nature of the game. Unfortunately, baseball isn't always as fun as it was when we were kids. There's a business part of it at this level."

In other moves to set its 25-man roster, Washington released right-hander Chad Durbin -- who signed with the Atlanta Braves -- and selected the contracts of first baseman Chad Tracy and outfielders Xavier Nady and Brett Carroll. Tracy's base pay this season will be $750,000, Nady's $700,000, and Carroll's $580,000.

Six players were sent to the disabled list: Wang, closer Drew Storen, and outfielders Michael Morse and Rick Ankiel on the 15-day DL, and first baseman Chris Marrero and pitcher Cole Kimball on the 60-day DL.