WASHINGTON -- The last time Jason Marquis took the mound for the Rockies he pitched brilliantly, allowing one run in seven innings with six strikeouts, but was somewhat overshadowed by the offensive output at the top of the order in the club's 10-1 win against Pittsburgh last Thursday.

In that game, leadoff hitter Dexter Fowler ignited the offense with a 4-for-5 night, scoring three runs, while Clint Barmes went 3-for-5 with three RBIs batting second.

Marquis takes the hill again on Wednesday for Colorado, in Game 2 of a three-game set with Washington, but it may be with a slightly retooled one-two punch behind him.

On Tuesday night, in a 4-2 win over the Nationals, Rockies manager Jim Tracy experimented with flip-flopping the two hitters that have been anchoring the offense, moving left fielder Carlos Gonzalez into the leadoff spot while sliding center fielder Dexter Fowler into the No. 2 hole.

The two have been among the most torrid hitters in the league this month.

Gonzalez, who was hitting .285 on the season coming into Tuesday's game and .400 in August, had been hitting second most of the time recently, including seven of his past eight starts. In fact, the Aug. 13 win against Pittsburgh marked the lone time in that span that Gonzalez was not starting in the two hole, batting eighth instead.

Fowler, meanwhile, has hit leadoff in 95 of his 107 games this season, batting .270 on the season and .410 in August.

But with right-handed Craig Stammen on the mound for Washington on Tuesday night, Tracy decided to shake things up a bit, especially since the switch-hitting Fowler was hitting .324 against left-handers, but just .246 against righties.

In three at-bats each against Stammen before he left the game in the sixth, Gonzalez went 0-for-3, but hit the ball hard each time. He later greeted left-handed reliever Sean Burnett to open the eighth inning with a homer, his third home run in as many games. Fowler went 1-for-2 with a walk, singling to left in the sixth and scoring the tying run in that inning.

With right-hander Collin Balester slated to go for the Nats on Wednesday, Tracy expects to use the same game plan.

Tracy felt that while he'd have been fine with both hitters staying right where they were, he was intrigued to see what might come with the tweak.

"Obviously this is the first time we've done this all year, but I'm interested to see it," he said. "I think it makes all the sense in the world because Carlos Gonzalez is doing all sorts of damage right now and has all that's necessary to be up at the top of the order."

And while Fowler had primarily seen time at leadoff in the big leagues, batting in the two-spot is not new to him.

"We know Dexter hit second a lot in the Minor Leagues behind Eric Young Jr.," said Tracy, referring to the second base prospect (and one of Fowler's best friends) who is one of the leading stolen base threats in the Minors. "So if this puts him in a place where some good things start happening as a result of our exploring this sort of thing, we're better served and both players are better served."

Sitting atop the National League Wild Card standings coming into Tuesday night's game and guaranteeing themselves at least one more night with that cushion, not to mention very much in the thick of the NL West race, Tracy knows that experimenting is fine, but not at the expense of winning.

"We've gotten to a point in time in the season where we're playing games to win, something a lot of people didn't think would happen," he said. "So it makes sense to continue to develop two very dynamic young players and also give ourselves a chance to continue to win games. I think this is a smart thing to try. We're not hurting ourselves one bit and we could possibly be enhancing ourselves even more."

Pitching matchup
COL: RHP Jason Marquis (13-8, 3.55)
Marquis' 13th win of the season against the Pirates Thursday marked a return to form for the All-Star pitcher and took him off a three-start schneid. He didn't have his best sinker working, but he was able to hold the Bucs to one run on three hits over seven innings. He worked ahead of hitters for much of the outing and benefited from excellent defensive play behind him. Marquis exploited the holes in the Pirates' swings, striking out six on the day, including three against cleanup hitter Garrett Jones.

WSH: RHP Collin Balester (1-2, 6.00 ERA)
In his most recent start against the Reds on Thursday, Balester pitched five innings and gave up five of the seven runs the Nationals surrendered. Four of the runs came on a pair of two-run homers by Jonny Gomes. The other was on a solo homer by Ryan Hanigan. One reason Balester has given up so many homers -- he has allowed nine in 24 innings -- is that his four-seam fastball has been too straight. Ironically, Balester said Thursday's start was the best his arm felt all season, but the box score tells a different story.

Tidbits
Left-hander Jeff Francis, who has not pitched this season as he recovers from a torn labrum, threw a 30-pitch bullpen session on Tuesday that consisted solely of fastballs. According to Tracy, Francis "came out of it fine and is progressing very, very nicely." The Rockies do not expect Francis to be activated this season, but are hoping he will be healthy to open 2010. ... Right-handed reliever Juan Rincon, who has been on the 15-day DL since Aug. 1 with elbow stiffness, will pitch two innings or 40 pitches (whichever comes first) on Tuesday night for Triple-A Colorado Springs. Tracy was also pleased with his progress.

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Up next
• Thursday: Rockies (Jason Hammel, 7-7, 4.73) at Nationals (Garrett Mock, 2-4, 5.27), 5:05 p.m. MT
• Friday: Rockies (Aaron Cook, 10-5, 4.31) vs. Giants (Jonathan Sanchez, 5-10, 4.49), 7:10 p.m. MT
• Saturday: Rockies (Jorge De La Rosa, 11-8, 4.58) vs. Giants (Joe Martinez, 3-1, 4.76), 6:10 p.m. MT