They're not the only big names missing from Mobile.
Michigan offensive tackle Jake Long, LSU defensive tackle Glenn Dorsey and Virginia defensive end Chris Long also aren't playing. That leaves the Senior Bowl without any of the top five senior prospects, as ranked by Frank Coyle of www.draftinsiders.com.
Ryan, rated by Coyle as the top overall prospect in the class, pulled out of the Senior Bowl last week. Brohm backed out over the weekend because of a lower leg injury.
Their absence leaves Kentucky's Andre' Woodson as the highest-rated quarterback at the Senior Bowl. Coyle rates Woodson as the No. 10 overall prospect in the 2008 draft class, though Woodson didn't want to speculate Monday on where he might end up next season.
"I'm excited to go anywhere," Woodson said after his South team completed its first practice. "There's still a lot of work to be done, and today you could tell with all the missed passes I had and all the other quarterbacks as well. It's a long road for us all."
Delaware's Joe Flacco and Tennessee's Erik Ainge are replacing Ryan and Brohm at the Senior Bowl. Flacco had planned on playing in the East-West Shrine Game last week until he received a Senior Bowl invitation.
Flacco, a Pittsburgh transfer, threw for 4,263 yards this season while leading Delaware to a runner-up finish in Division I-AA. Coyle has rated Flacco as the No. 6 quarterback prospect in this class (behind Ryan, Brohm, Woodson, Hawaii's Colt Brennan and USC's John David Booty).
(Adam Gorney of GatorBait.net contributed to this report)