Pregame notes on Uggla, Werth, Span, Harper, Roark and Martin

Nationals manager Matt Williams was asked during his pregame media session Thursday about second baseman Dan Uggla and how the veteran must change his preparations each game now that he comes off the bench.

"It's never easy. Being an everyday player his whole career, it's not easy to learn how to do it," Williams said. "The objective when he walks up there is to be him and not try to be something that he is not. His thought process when he goes up there is(to) get a good one to hit and whack it like he always does.

"He'll be aggressive from the first pitch, like he always hit. It's been the last three games, but it doesn't mean it'll be all the time either. He'll get some starts as well. Last night, we needed to get T-Mo (Tyler Moore) an at-bat, so we got him in there."

Left fielder Jayson Werth is off today. Williams confirmed that the Nats still want to be careful with Werth as he comes back from shoulder surgery and not play him every day.

"He's going to have to have an occasional day," Williams said. "He didn't have spring training, if you will. He goes through that regular spring training soreness and it's even more monumental because it's condensed (amount of time)."

So why is Denard Span playing so much?

"Denard was able to do more," Williams said of Span's rehab process. "He was able to do more things. He got all of his running in, he got all of his hitting in, all of that. We'll look to give him a day here and there, too, but it's a little different situation."

Williams said Bryce Harper would play center field sometimes when Span is out. Werth could move back to right field in those situations "depending on the day," or Clint Robinson can play in right.

Williams is happy with reliever Tanner Roark and said the Nats will take their time in adjusting the bullpen with Craig Stammen out following flexor muscle surgery. With Stammen out, have Roark's responsibilities in the bullpen changed?

"Yeah, it does. We saw it a little bit of it the other night," Willaims said. "More of a one-inning stint type situation. He was available last night, too. But we want to make sure we ease him in to that if we can because he's been a starter and because he's been a longer guy. The resiliency is key. Depends on pitch count and the number of pitches the day before. He said he felt pretty good yesterday, so with that day off he certainly available to do that today, too."

Roark even told me earlier in the week that Rafael Martin can be a guy who can pitch two innings or more in one outing. But Williams also noted that the Nats hope they don't have to use a long guy in the bullpen too much this season with such a powerful starting rotation that can usually take the opponent to the seventh inning.