By OnMilwaukee Staff Writers   Published Sep 18, 2008 at 5:09 AM

CHICAGO -- Even with a 6-2 victory over the Cubs, the Brewers playoff hopes took another hit Wednesday night at Wrigley Field.

Starter Ben Sheets left the game after just two innings, complaining of stiffness in his right forearm. It was the second time this month that he's left a game early; the other coming on Sept. 1 against the Mets, when he exited after five innings with a sore groin.

Sheets said after the game that he had been experiencing discomfort since a start in St. Louis on Aug. 26. An MRI performed a little more than a week ago showed no structural damage, according to Sheets.

"My elbow has been bothering me for awhile now," said Sheets. "We've been fighting it off for awhile. I couldn't get the ball where I needed."

The discomfort resurfaced in the first inning. Facing Derrick Lee, Sheets said he felt a "tug" in his right arm. Interim manager Dale Sveum quickly got September call-up Mark DiFelice ready in the bullpen, and replaced Sheets at the start of the third inning.

With the Brewers trailing the front-running Mets by a half-game in the Wild Card race, and the Cubs by eight games in the National League Central, Sveum was understandably concered about Sheets' availability during the final 10 games of the season.

"When one of your best pitchers is sore and can't get loose ... you worry about it," Sveum said. "He was fine in his bullpen but something tightened it up."

Staked to an early 3-0 lead thanks to Prince Fielder's first-inning, three-run double, Sheets allowed just one hit in his two innings of work -- a home run to Aramis Ramirez -- to go along with two strikeouts. He threw just 54 pitches.

In Sheets' absence, the bullpen stepped up.

DiFelice pitched two scoreless innings and earned his first career major league victory after allowing just one hit and striking out a pair. He had waited nearly a decade to make his major league debut and, when he was returned to Class AAA Nashville on June 29, he never thought he would be taking the mound in a game as important as Wednesday night's.

"It didn't hit me until I was on the mound that I was actually pitching," DiFelice said. "Being a September call-up, knowing my role is pitching later in games, for them to go to me in that situation felt great.

"This is a dream come true for me."

For the second straight game, Fielder sparked the offense. The first baseman was 3 for 4 with a pair of doubles and three RBI. He extended his hitting streak to eight straight games and is hitting .483 during that stretch with four homers and 10 RBI. Against the Cubs this year, Fielder is batting .405.

"I'm just trying to see it and hit it," said Fielder. "I'm trying to not make it too difficult. I think as a team, when you start struggling, you try to make things more serious than they are. I'm just trying to make it simple."

The victory - just the fourth this month for the Brewers - wouldn't have been possible without an impressive effort from the bullpen. Aside from DiFelice's performance, the relivers combined to hold the Cubs to just a run on five hits with six strikeouts.

Todd Coffey, Carlos Villanueva, Mitch Stetter, Eric Gagne and Guillermo Mota all pitched scoreless innings. Salomon Torres, working for the first time in a week, came on to work the ninth and allowed the Cubs' only other run on a botched double-play that could have ended the game.

Sveum received a beer shower in the locker room in celebration of his first victory as manager, but with just 10 games to play, he put a quick end to the party.

"From here on out, it's 'today'," Sveum said. "You worry about tomorrow, tomorrow. Every game we play from here on out is a playoff game."