While the Westgate Las Vegas Superbook installed Spieth and McIlroy as co-favorites last month, McIlroy will start the week as a 7/1 betting favorite. Spieth is next at 8/1, followed by world No. 1 Dustin Johnson and recent winner Hideki Matsuyama at 12/1.
McIlroy's dominance at Quail Hollow is well-documented, with two wins and six top-10s in seven starts, while Spieth has won two of his last three starts, including The Open.
Here's a look at some of the odds on other contenders, as Quail Hollow gets set to host the season's final major for the first time:
7/1: Rory McIlroy
8/1: Jordan Spieth
12/1: Dustin Johnson, Hideki Matsuyama
15/1: Rickie Fowler
20/1: Jon Rahm