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4/18/2014 12:55 A.M. ET

Results positive for Fister in simulated game

WASHINGTON -- Right-hander Doug Fister pitched in a simulated game on Thursday and worked two innings without any problems, according to manager Matt Williams.

Fister will have another simulated game in five days, pitch three innings and hopefully start a rehab assignment after that. Fister, who is on the disabled list because of a lat strain, could return to the Nationals within 20 days. He will have at least two rehab starts before returning to the club.

"We have to build [up Fister] like we [tried to] build him [up] this spring," Williams said. "I think he is a little bit ahead of the game in that regard. I would like him to get five innings somewhere to make sure he can up that pitch count."

Nationals ready to resume rivalry with Cards

WASHINGTON -- If you include Game 5 of the 2012 National League Division Series and last year's regular season, the Nationals have now lost eight straight games to the Cardinals following Thursday's 8-0 defeat in the opener of a four-game series.

Is it safe to a say the Cardinals have their number? The answer is no, according to Nats first baseman Adam LaRoche.

"My question is, how many games have we lost to St. Louis this year? It's a new year, we turn the page. We are 0-0 against St. Louis. We have haven't played them yet," LaRoche said prior to Thursday's contest at Nationals Park. "We have experienced some things with St. Louis that don't sit well with us."

The worst loss to St. Louis was arguably Game 5 of the NLDS on Oct. 12, 2012. The Nationals had a 6-0 lead and lost, 9-7. The game ended Washington's postseason run.

"I look back at a lot of those games and we beat ourselves," LaRoche said. "I think comparatively, we are right there with them and I would think they would say the same thing. If you want to look back, they have our number a little bit, but we are 0-0 [this year]."

Nationals manager Matt Williams gave the Cardinals credit for playing the game the right way. Entering Thursday's action, the Cardinals were 9-6 -- two games behind the Brewers in the National League Central standings.

"It starts with their rotation," Williams said about the Cardinals. "They have one of the best catchers [Yadier Molina] in the league and he runs a great game -- both offensively and defensively. They have power, they have some speed, they play exceptional defense. All of that combined is the reason they are at where they are at. Do we measure ourselves? I guess, yes, but ultimately we have to worry about ourselves and play the game the way we want to play it in order to have a chance to beat them."

Despite quad issue, Harper plays vs. Cards

WASHINGTON -- Despite experiencing left quad tightness, Nationals outfielder Bryce Harper was in Thursday's lineup and playing left field against the Cardinals.

Harper went 0-for-4 in the Nats' 8-0 loss.

Manager Matt Williams isn't worried that the injury could get worse. He pointed out that Harper could run the bases 100 percent. Williams also said that Harper is guarding the injury against plays he doesn't have to go all out on.

"It's tight on him, but we have to make sure that we are taking the right precautions so he could continue to play. We don't want to get it too bad," Williams said. "The thing that Bryce has to do is make sure he monitors [the injury] himself. He has been playing a lot of center field, he has been running the bases a lot. Those are all good thing and he has done it fine."

Span sees action with first rehab assignment

WASHINGTON -- Denard Span played in his first rehab assignment for Class A Hagerstown and went 1-for-2 with two walks, three runs scored and an RBI. Span is on the seven-day disabled list because of a concussion. The Nationals are hoping he can be activated on Saturday.

The injury occurred in the eighth inning of last Friday night's 7-6 loss to the Braves. With runners on first and second and two outs, Span singled to center field off of right-hander David Carpenter, scoring Bryce Harper. Span was awarded second base for colliding with second baseman Dan Uggla, who was charged with interference.

Span also sustained a thigh injury on the play. He said the thigh injury hurts more than the concussion.

Bill Ladson is a reporter for MLB.com and writes an MLBlog, All Nats All the Time. He also can be found on Twitter @WashingNats. This story was not subject to the approval of Major League Baseball or its clubs.