As comfortable as the Red Sox have looked while walloping the Blue Jays by an aggregate score of 18-5 in the first two games of this series, they know that a very big obstacle stands in the way of a three-game sweep.

The name of that obstacle is Roy Halladay, one of the finest pitchers in baseball. Toronto's ace can get a team out of a slump in a hurry, and that's what the Jays, losers of eight in a row, are banking on.

"Halladay has been one of the best," said Sox manager Terry Francona. "We've seen him enough. Like I say, we'll have our work cut out for us."

But the Red Sox have a pretty good pitcher of their own on the mound in knuckleballer Tim Wakefield. Don't let Wakefield's 3-3 record fool you. His 2.11 ERA is far more indicative of the way he's pitched.

Wakefield has allowed three earned runs or less in all six of his starts this season.

The Red Sox have won 15 of their last 20 games.

Pitching matchup
BOS: RHP Tim Wakefield (3-3, 2.11 ERA)
The knuckleballer was sterling his last time out, tossing seven scoreless innings to beat Minnesota at the Metrodome and end his two-game losing streak. Wakefield's ERA is a much better indication of how well he's pitched than his won-loss record, since the Red Sox are continuing their trend from last year of failing to score runs for him. In his last 11 starts -- going back to July 17 -- the Sox have scored 16 runs with Wakefield in the game. In his career against Toronto, Wakefield is 13-8 with one save. He beat the Jays, 4-1, with seven strong innings in Toronto on April 18.

TOR: RHP Roy Halladay (4-1, 3.59 ERA)
Halladay matched the second-worst start of his career on Saturday in Texas, allowing nine runs on 12 hits in 5 1/3 innings. Halladay took a no-decision in a 5-3 loss to Boston at Rogers Centre on April 19. He allowed two runs on six hits in 7 1/3 innings and left with a 3-1 lead that the bullpen was unable to hold. Five days later at Fenway Park, Halladay gave up three runs in eight innings, but was a 10-3 winner. He is 1-0 with a 2.93 ERA against the Red Sox in two starts this season, and 9-7 with a 4.46 ERA in 29 career appearances against Boston.

Player to watch
David Ortiz's average is up to .311 after a 4-for-5 performance on Wednesday.

On the Internet
 MLB.TV
 Gameday Audio
•  Gameday
•  Official game notes

On television
• NESN

On radio
• WRKO-680 AM, Spanish Baseball Network (Español)

Up next
• Friday: Red Sox (RHP Julian Tavarez, 1-3, 6.48) vs. Orioles (LHP Brian Burres, 0-1, 3.71), 7:05 p.m. ET
• Saturday: Red Sox (RHP Curt Schilling, 4-1, 3.28) vs. Orioles (RHP Steve Trachsel, 1-3, 3.70), 1:05 p.m. ET
• Sunday: Red Sox (RHP Josh Beckett, 7-0, 2.51) vs. Orioles (RHP Jeremy Guthrie, 2-1, 4.64), 2:05 p.m. ET