Mattheus knows his role might change a bit (we're under way)

LAKE BUENA VISTA, Fla. - The rain is still falling, and we're in a delay that might not be lifted anytime soon. Radar over the Orlando area shows plenty of rain is still coming, so Ross Detwiler might have trouble getting his two or three innings in this afternoon. Ryan Mattheus takes a look around the Nationals' clubhouse these days and sees a lack of southpaws. Sean Burnett departed via free agency this offseason. So did Tom Gorzelanny. Michael Gonzalez then joined Gorzelanny in Milwaukee. OK, so the Nationals have Zach Duke signed to a major league deal, and a host of non-roster lefties are fighting for what will likely be the final spot in the bullpen. But Mattheus knows that given the way the bullpen is currently constructed, he'll be one of the right-handers that manager Davey Johnson will count on to get tough left-handed hitters out this season. And since he's held lefties to a .214 average over his career, Mattheus is just fine having that responsibility tossed on his shoulders. "Before we lost Sean and Mike and Tom, I didn't really know that I was that good against lefties," Mattheus said. "Just looking at the numbers, just looking at the guys we have down there, no one's actually told me that I'm going to be facing left-handers, but I'm going to take it upon myself to be ready to get them out." The Nationals had negotiations with a few left-handed relievers this offseason, but general manager Mike Rizzo didn't end up becoming a major player for Burnett or forcing matters with J.P. Howell. Instead, he opted to bank on the idea that Mattheus, Tyler Clippard, Craig Stammen and others would be able to pick up the slack against left-handed hitters. "One of the reasons why we felt not under the gun to sign those guys is because all my right-handers basically were very successful against left-handed hitters," Johnson said. "If you look at Clippard's numbers, you look at (Drew) Storen, you look at Mattheus, you look at Henry (Rodriguez), Stammen, all of them are pretty good both ways. "I do like to match up late, and I won't have that option, so that'll be a little different. I'll be matching up, 'Do I want them to hit a sinker or a split or a changeup or a 100 mile-an-hour fastball?' " In his career, Clippard has held lefties to a .186 average, and Storen has limited left-handed hitters to a .229 mark. Stammen, working full-time in relief last season, saw lefties hit just .198 off him. Knowing that his role could change slightly this season due to the lack of southpaws, Mattheus has come into camp specifically trying to work on locating on the inner-half to left-handed hitters. He's trying to focus on moving his sinker to that side of the plate and staying away from strictly working on the arm-side. "With right-handers I can do that, I can just keep going further in, but lefties, they'll go out there and get you, so I'm working on keeping them honest inside," Mattheus said. From Mattheus' perspective, Rizzo and Johnson not forcing the issue when it comes to signing another left-hander this offseason shows that they have faith in him, along with the other right-handers in the 'pen, to get the job done themselves. "That's absolutely a great vote of confidence that he's not worried about us getting left-handers out," Mattheus said. "I take it as a compliment when he gives me a ball in a big situation to go get a Ryan Howard or an Ike Davis out." Update: The rain delay is nearing its end, and today's contest is expected to begin at 2 p.m. Update II: We're under way. A rain delay of exactly an hour is behind us and we've got baseball at Champion Stadium.