Right now, Rice is looking at the possibility of being the 4th or 5th receiver for Denver.

http://sports.espn.go.com/nfl/news/story?id=2151966

I'm not sure how well the other guys did, or how poorly Jerry Rice did (and those major caveats apply to everything said after), but I cannot imagine using a random, no-name rookie for my 3rd receiver instead of Rice. I would imagine just the sheer presence, intelligence, and knowledge of the game would make him the superior 3rd option.