Williams on Desmond's day off, Zimmerman, Gonzalez and Souza

Manager Matt Williams gave shortstop Ian Desmond off from the starting lineup Thursday in the final game of the series against the Diamondbacks. Danny Espinosa will play shortstop today for the Nationals, while Asdrubal Cabrera remains at second base.

So on Desmond's bobblehead day at Nationals Park, the shortstop gets a well-deserved game off.

"I figured it would be good to give him today," Williams said. "Definitely didn't want him to miss the Giants series, give him today through the next six (games) with another off day through the following six (games) then we'll see where we're at."

Williams also explained why he decided to keep Cabrera at second base today and have Espinosa play short.

"Couple of reasons. Not trying to upset the apple cart too much," Williams said. "Asdrubal is playing so well at second base we don't want all of sudden (to) flip things. Danny's a really good defender. He's played short with this team before. He knows Gio from playing out there. Rather than flip two guys we just decided to leave Asdrubal where he's at and play Danny at short. He's a really good shortstop anyway."

Today is a big game for left-handed starter Gio Gonzalez, who is the only starter that has struggled with his command for a few games in a row recently. Gonzalez has lost his last five decisions and hasn't recorded a win since July 5. Gonzalez has given up 14 earned runs in the last four games. He also has gone six or more innings in only two if his last six starts.

"I just think it's curveball command," Williams said. "If he can land a curveball early and he gets the feel for it. They have a young team over there, guys that really hit the fastball well. So if he can land that it gives them another pitch to think about. It also lets his changeup work really good too."

Williams confirmed that Ryan Zimmerman, who is on the disabled list with a right hamstring strain, did some light throwing during extended pregame Thursday. Williams said it's the first step in Zimmerman's progression to eventually get back on the field.

"He threw, yeah. It's part of it, though," Williams said. "You have to use that muscle to throw. It's part of the deal. That's part of the strengthening process in getting him back to some baseball activity and working through that. That's the early stages of it, but it's a step for sure."

"He's not running yet. It's one thing to do hamstring exercises, but to be sport-specific is key too. This is the first day. It's nice and easy but it allows him to do some baseball-related activity, which is good. We want to be cautious and diligent about his rehab and making sure he's good to go when he's good to go."

Williams said the steps in the progression that are down the road for Zimmerman include: taking batting practice, running at full speed and running the bases. The third step is obviously the most critical to making sure Zimmerman's hamstring is fully healthy.

"The biggest test because he has to react and turn and create different angles and things to turn a base," Williams said. "That's generally - with any pulled muscle, especially legs - the final step that he would have to go through before he would go and play."

Outfielder Stephen Souza Jr. will begin a rehab assignment tonight with low Single-A Hagerstown. Souza has been on the disabled list since Aug. 10 with a left shoulder strain.

"We'll just see how he plays," Williams said. "He's got to progress back to nine innings and get through and get four at-bats and does all of his pregame stuff and postgame work and all of that to make sure that he's good to go. He's scheduled for the next week or so and we'll see how he reacts. But he needs a few games (after) sitting around, not being able to swing. He needs to get his timing back."