Burnett, a former Marlins hurler, joins 2003 Cy Young winner Halladay atop the Blue Jays' rotation.
Carlos Zambrano and <br>Mark Prior
With Kerry Wood often hurt, the title of co-ace falls to the durable Zambrano, who has compiled at least 200 innings in three consecutive seasons.
Randy Johnson and <br>Mike Mussina
These two won't be lacking run support with the lineup the Yankees have.
Mark Mulder and <br>Chris Carpenter
Carpenter, the reigning NL Cy Young winner, pairs up with Mulder to make the Cardinals the heavy favorites to win the NL Central for a third consecutive year.
John Lackey and <br> Bartolo Colon
This duo combined to win 35 games for the AL West champions last season. Colon was named the AL Cy Young winner for his 21-8 record and 3.48 ERA.
Pedro Martinez and <br>Tom Glavine
These wily veterans boast five Cy Young awards between them.
Tim Hudson and <br> John Smoltz
Smoltz has gone from ace to closer and back again. Formerly of the A's, Hudson boasted a 106-48 career record heading into this season.
Andy Pettitte and <br> Roy Oswalt
Oswalt is 4-0 in seven career postseason starts while Pettitte is 14-9 in 34 playoff outings.
Barry Zito and <br> Rich Harden
The 25-year-old Harden already has supplanted former Cy Young winner Zito as the ace of the staff.
Josh Beckett and <br> Curt Schilling
Josh Beckett came over in an offseason trade from Florida to give Boston two former World Series MVPs.