(SportsNetwork.com) - The scuffling Philadelphia Phillies look to stop the bleeding when they open a three-game series Tuesday versus the Cincinnati Reds at Citizens Bank Park.

The Phillies have lost seven in a row and nine of their last 10 games, and were swept in three games by the Colorado Rockies this weekend. In a 4-1 decision on Sunday, Phillies starter Jerome Williams was touched for all four runs and eight hits, including two homers, in five innings.

Cameron Rupp knocked in the lone run for the Phillies, while Cody Asche and Odubel Herrera ended with two hits apiece. Philadelphia threatened in the home seventh, loading the bases on a walk and two singles with no outs, but Rockies reliever Brooks Brown replaced Chris Rusin and struck out the side.

"That was the big play in the game, bases loaded with no outs," said Phillies manager Ryne Sandberg. "It was our best chance of the day, so that was a disappointing half of an inning for us."

The Phillies, who will also host San Francisco on this nine-game stay, have scored just four runs in the last four games and will send Sean O'Sullivan to the mound Tuesday. O'Sullivan has a 1-4 record and 4.81 earned run average in six starts and dropped his second outing in a row Wednesday against the New York Mets.

O'Sullivan was tagged for a season-high seven runs and 11 hits in 5 2/3 innings. The right-hander will make his second career start against the Reds and gave up one run over six innings in the first encounter.

The Reds will try to stop a seven-game road losing streak in the City of Brotherly Love and have won three in a row and four of five games overall.

Cincinnati pulled off a three-game weekend sweep of the Washington Nationals with Sunday's 8-2 triumph, as Brandon Phillips and Todd Frazier both homered and combined for five hits, four RBI and four runs scored. Jay Bruce had a two-run double during a six-run seventh inning for the Reds.

"That old saying hitting is contagious, same kind of thing goes with runners in scoring position, everybody relaxes, understands that we don't need to get outside our strike zone and let the pitch come to you and attack," Frazier said.

J.J. Hoover picked up the win in relief by recording the final two outs in the top of the seventh. Mike Lorenzen walked six over his 6 1/3 innings, but allowed one hit and two runs while striking out four.

The Reds will try to keep the momentum going Tuesday in the return of starter Johnny Cueto. Cueto has been bothered by an elbow issue and last toed the rubber in a 3-0 loss at Kansas City on May 19, when he lasted seven innings and gave up three runs. Cueto said every pitch "was good" in Sunday's bullpen session.

Cueto, a right-hander, has struggled in eight career starts against the Phillies, going 1-4 with a 5.52 ERA.

Cincinnati and Philadelphia split six meetings a season ago and will play three more times at Great American Ball Park next week.