Adam Caplan of SiriusXM NFL Radio reports that 21 teams showed up and saw Gordon run a 4.52-second 40-yard dash. While that isn't quite as fast as some pre-draft buzz indicated, it's plenty quick for a 6-foot-3, 224-pound athlete.
Caplan also reported that Gordon had a 36-inch vertical leap and 10-foot-1 broad jump, which are very good numbers.
In the traditional draft process, the Pro Day is not the end-all, be all. It's a little more important for Gordon considering that teams haven't seen him play in 2010. This 40-yard time doesn't figure to increase the early round hype surrounding Gordon, but we doubt that it will hurt his buzz.
UPDATE: Caplan later reported that Gordon pulled his left quadriceps during his workout.