"I changed my grip with it so I can get a bigger difference in velocity. In the end, I was told I was getting it a little bit better," Haren said. "When your arm feels fresh, it's not just the fastball, everything else is going to feel a little bit better."
Haren, who is on the disabled list because of shoulder inflammation, said resting the shoulder did a world of good. The ball came out of his hand a lot easier, and he was able to raise his arm a lot more while throwing the ball.
"With the rest, I was going to feel fresh. Hopefully that's what I needed to get back doing some good things in helping the ballclub," Haren said. "I'm getting the ball to where I usually do. Before, the last couple of games, I always long tossed between starts and before the game, and it was a struggle to get the ball there. My arm is moving faster."
Moore was impressed by what he saw from Haren.
"The cutter was very late. The splitter, he was throwing for strikes and a chase pitch. It was real good. I was impressed with what he had," Moore said. "It was hot. He kept wanting the ball. He is a competitor, whether we are doing a [simulated] game. He wants to be on the mound, he has fun with it. He wants to go at guys. He was great."
Haren is expected to have a bullpen session in two days and hopes to start on Tuesday against the Phillies.
Bill Ladson is a reporter for MLB.com and writes an MLBlog, All Nats All the time. He also could be found on Twitter @WashingNats. This story was not subject to the approval of Major League Baseball or its clubs.