The big reason was that he had sure hands (until his senior year) and also because we didn't really have anyone else. Not really because he was an amazing PRer. #1 job is to catch it. He was usually good at that and that's why he was back there. Obviously his senior year he struggled a lot more to hold onto it and also let more of them go possibly due to lack of confidence.

Just because he's been the "best" in Bronco's era, doesn't really make him an amazing punt returner. He was good/ok. Nothing against him. Just not that incredible.