Dempster made it to the postseason with the Chicago Cubs twice in his career. In Game 2 of the 2007 NLDS in Arizona, Dempster pitched an inning of relief in an 8-4 loss to the D-backs, picking up two strikeouts.
In 2008, old friend Derek Lowe, pitching for the Dodgers, outdueled Dempster in a 7-2 Dodgers win over the Cubs in Game 1 of the NLDS. Dempster had 7 walks in 4 2/3 innings in that start and gave up a homer to James Loney.
Dempster is 0-1 with a 6.35 ERA in his postseason career. Dempster is slated to pitch out of the bullpen for the Red Sox in the playoffs.