WASHINGTON -- During his professional baseball career, Nationals right-hander Jason Marquis has been told by many in the game that if a player is injured, surgery is the last resort.

In Marquis' case, he has opted not to have surgery to get rid of bone chips in his right elbow. Marquis, who was given a cortisone shot Wednesday, will not throw for seven to 10 days. He will begin a throwing program soon thereafter. The Nationals are hoping that Marquis will be back on the mound within four to six weeks.

"If there is a conservative approach, then you do it." Marquis said. "We know what's in there. We know what the problem is. We attacked it with some cortisone, we drained a little fluid out of there. Hopefully the swelling goes down. The restrictions on the elbow aren't there. ... Hopefully, I'll be back sooner rather than later."

Marquis declined to say when he started to feel pain in the elbow, or give excuses for his disappointing performance on the mound. This past Sunday was arguably the worst outing of his career. He gave up seven runs against the Brewers and became the first starter in Nationals history to not record an out. Marquis threw 28 pitches, 13 strikes, in that tough start, and has given up 19 earned runs in 8 1/3 innings for Washington this season.

"I'm not going to make excuses. I just wasn't good," Marquis said. "Were there restrictions on my elbow? Yeah, but if I'm going to go out there and pitch through things, I still have to get it done, and I feel I can put my team in a position to win. I move on and try to get this elbow better so I'm effective next time I take the ball."

General manager Mike Rizzo said the Nationals gave Marquis a thorough examination before he signed a two-year, $15 million deal last December. Rizzo believes that Marquis can be productive when the righty returns to the mound.

"I always say, 'I want Jason Marquis to be Jason Marquis,'" Rizzo said. "A healthy Jason Marquis -- I think he is going to be what he always is: That 200-innings guy that could win 12 to 15 games with a low 4.00 ERA. That's what we got in the winter and that's what he could be."

Zimmerman sits out series opener vs. LA

WASHINGTON -- Nationals third baseman Ryan Zimmerman didn't start in his second successive game after tweaking his right hamstring Wednesday against the Rockies. Manager Jim Riggleman said Zimmerman is available to pinch-hit and most likely will not play Saturday afternoon against the Dodgers.

However, Zimmerman said the hamstring is getting better. It got better to the point where he was able to take light batting practice in the cage before Friday's game. He did not appear to be in any pain.

"[The hamstring] is doing well," Zimmerman said. "It felt 100 percent better than it did yesterday. Yesterday, I was pretty sore. I woke up today and it felt pretty good. Maybe we will fire away tomorrow."

Tracy sees Riggleman's impact on Nats

WASHINGTON -- Before watching his team split a four-game series in Washington, Rockies manager Jim Tracy noticed how much of an impact manager Jim Riggleman has on the Nationals, who are currently 8-8 to start the season. A year ago, Washington was 3-11 to start the season.

Tracy and Riggleman are good friends. Riggleman was Tracy's bench coach for four years when both were with the Dodgers.

"He's a terrific baseball man. He is very good with the X's and O's," Tracy said. "He's already laid his imprint on who he is and what he's all about. He's a very, very capable man. I see a greater sense of awareness right now, on the players' parts, of recognizing what it is they have to do in different situations.

"They have good players. They're headed in the right direction. There's a higher energy level. There's a lot of things that look, to me, to be a lot different."

Morse heads to extended spring training

WASHINGTON -- Nationals outfielder Mike Morse, on the disabled list because of a left calf injury, was sent to extended spring camp. He will get at-bats at the team's complex in Viera, Fla., and then go to the Minor Leagues for a rehab assignment. There is no timetable as to when Morse will return to the big league club.