NEW YORK -- He isn't hurt, but the Nationals don't understand why right-hander Daniel Cabrera isn't throwing with the same velocity when he was with the Orioles.

Cabrera, whose fastball is often clocked in the high 80s to low 90s, is trying to be too perfect on the mound. The 27-year-old told manager Manny Acta and pitching coach Randy St. Claire that he is working on decreasing his walk totals from previous years. He averaged 95 walks in his previous five seasons.

But Acta and St. Claire explained to Cabrera that he shouldn't worry about the walks. Just throw gas. For the season, Cabrera has seven strikeouts and 12 free passes in 18 1/3 innings.

"We are trying to find out where that comes from exactly, what is it that he is trying to do," Acta said. "He indicated to us that he was trying to throw more strikes. But the fact is, he is still a little bit on the wild side, and the velocity is not the same. Randy is just trying to work with him and convince him to go back to his old self and let the ball fly, because he will be more effective by throwing in the mid-90s like he used to."

Earlier this month, St. Claire said he declined to talk to Cabrera about his walk totals.

"I have not mentioned one thing about walks to him, because, to me, that isn't the concern," St. Claire said. "To me, I want to see him get 95, 96 mph back. So the only way he is going to do that is be aggressive. When you throw 96 mph, you can walk a guy. It's hard to hit that pitch. There are a lot of guys that throw 90-91 mph."