Edinson Volquez (13-5, 2.93) takes the mound for Cincinnati trying to break out of a personal rut.
The All-Star right-hander has been anything but in four starts since the break, allowing 15 earned runs and 30 hits in 20 1-3 innings. On Tuesday, he gave up five runs and a season-high nine hits over five innings in an 8-1 home loss to Milwaukee.
Volquez hopes for a better outing Tuesday, though he hasn't received a decision in two career starts - both this season - versus Pittsburgh. He gave up three runs and seven hits in 5 1-3 innings of a 6-5, 11-inning home defeat on July 1.
Jeff Karstens (2-0, 0.00) looks to continue his outstanding pitching for the Pirates.
The right-hander has tossed 15 scoreless innings in two NL starts since he was acquired from the New York Yankees on July 26 in a six-player deal for outfielder Xavier Nady and reliever Damaso Marte.
Karstens was nearly perfect on Wednesday, setting down the first 23 batters in order before Chris Young doubled with two outs in the eighth inning. He finished with a two-hitter in a 2-0 victory, walking one and striking out four.
Karstens will make his PNC Park debut, as well as his first career appearance versus the Reds.
Left fielder Dunn, eligible to become a free agent after the season, was traded Monday to the Arizona Diamondbacks for Class A right-handed pitcher Dallas Buck, two other minor league prospects and cash.
Dunn, tied for the major league lead with 32 homers, hit 40 or more home runs in each of the last four seasons, drove in more than 100 in three of the last four seasons, walked more than 100 times in five of the last six seasons and scored 100 or more runs in three of the last four years (99 in the year he didn't).
Dunn, 28, is the third significant player to be moved by the Reds in little more than a week. Outfielder Ken Griffey Jr. was traded to the White Sox at the July 31 trade deadline, and catcher David Ross was designated for assignment Sunday.
General manager Walt Jocketty, who took over the team in late April, has watched his team lose 14 of its last 16 games, including the last six. The Reds have fallen into last place in the National League Central.
With 10 prospective free agents remaining on the roster, a makeover of the team is expected between now and the end of the season, with more changes due in the off-season.
--RF Jay Bruce went 0-for-4 with three strikeouts Sunday, ending his career-best 13-game hitting streak, the best for an NL rookie this season. Earlier, he had a 12-game hitting streak.
--RHP Edinson Volquez, pitching on two extra days of rest after winning only one of his last five starts, faces the Pirates in PNC Park on Tuesday, his third start this year against the Pirate. In the first two, he received no-decisions and the team lost both games.
--INF/OF Jolbert Cabrera homered Sunday, his first major league home run since Sept. 5, 2004 for the Mariners against the White Sox.
--C Ryan Hanigan had two hits in his 2008 major league debut Sunday, including his first home run after going 3-for-10 last September. He is expected to do the bulk of the catching the rest of the season.
--OF Corey Patterson, expected to get more playing time after the trade of LF Adam Dunn, was 3-for-21 on the just completed 1-6 homestand and is hitting .190 for the season.
BY THE NUMBERS: 0 -- Number of times RHP Homer Bailey pitched beyond 6 1/3 innings in his eight starts in the majors this year.
QUOTE TO NOTE: "Actually, I'm looking forward to it. It is not the big leagues, but the team is seven games up and in the playoff hunt and they are having fun and morale is good." -- RHP Homer Bailey on his demotion to Class AAA Louisville.