An 11-game winner across 29 starts in 2009, Ohlendorf has won just once in 25 starts since, going 1-11 in 21 outings last season and 0-1 in four starts thus far in 2011.
He debuted for the season on April 3 at Wrigley Field, allowing eight hits and four runs in six innings of a game the Pirates ultimately won, 5-4.
He made one more start on April 8 against Colorado and got a no-decision, then was shelved for several months with a shoulder ailment before returning to the majors with starts against Milwaukee and Houston at the end of August.
In 18 2/3 innings this season, he's allowed 27 hits and 16 runs with eight walks and 15 strikeouts.
Lifetime against the Cubs, Ohlendorf is 1-0 in four starts with a 2.42 earned run average.
Burres (1-0), making his first appearance in the majors this season, gave up one run on five hits to pick up the win. The southpaw went 4-5 with the Pirates over 20 appearances (13 starts) in 2010.
Pittsburgh, which snapped a five-game skid, lost outfielder Andrew McCutchen in the first inning. Ryan Dempster threw a fastball that hit the top of McCutchen's left hand. He was able to run the bases but did not take the field in the bottom half of the inning.
Alex Presley moved from left field to center and Tabata came off the bench to play left. Tabata did not start because of an injured wrist.
Carlos Pena homered for the Cubs, who have lost two in a row since a two-game winning streak.
Dempster (10-11) gave up three runs on seven hits over 6 1/3 innings to take the loss. He struck out nine and walked one in his third straight defeat.
The Cubs had won four straight over the Pirates.
Right-hander Casey Coleman takes the mound for the Cubs with an eye on a first win since May 19.
The Florida Gulf Coast University product was 2-3 in the season after a 5-1 defeat of the Florida Marlins in Miami, but is 0-4 in seven outings since.
He pitched seven innings and allowed three runs in a 3-2 loss at Milwaukee in his last start on Aug. 28, walking three batters and striking out six.
Coleman tossed one-third of an inning in relief against the Pirates on May 27, his lone career meeting with Pittsburgh in 26 major-league appearances.