Chicago looks to complete a three-game sweep of the defending World Series champions at Wrigley Field.
Chicago has won both games in the first series between the teams since the 1918 Fall Classic and has won 12 of its last 16 overall.
Left-hander Glendon Rusch will try to complete the sweep Sunday. Unbeaten in his last six outings, Rusch has not allowed more than two earned runs in any of his seven starts this season.
He yielded two earned runs and four hits over six innings Tuesday, but did not receive a decision in Chicago’s 6-4 loss to Toronto.
The Red Sox haven’t figured out a way to stop the Cubs, who had 20 hits in Friday’s series opener and 12 more Saturday.
The Red Sox have dropped five of their last seven games.
“We talk about being just good enough to win. I agree that right now we’re just good enough to lose and that’s not good,” Red Sox manager Terry Francona said. “Consistency at this level is so big and we’re having a heck of a time finding it.”
Struggling knuckleballer Tim Wakefield will take the mound for Boston on Sunday, hoping to snap a five-start losing streak.
Wakefield, who has surrendered 26 earned runs in 28 1-3 innings during the skid, allowed five runs and seven hits over 5 2-3 innings in a 7-1 loss at St. Louis on Monday.
The slump is Wakefield’s worst since a seven-game skid from Sept. 18, 1995 to April 20, 1996.
“I felt like I pitched OK until that last inning and gave up a pretty cheap run,” Wakefield said. “I think my last time out I didn’t have good stuff, but the other starts I just couldn’t catch a break.”