I've gotta say, seeing this kind of tweet makes me a happy 49ers fan. For those that don't remember, The Hill is a well known area where Jerry Rice used to run (and I believe still might run on occasion). It was a notoriously brutal run that was a key part of his conditioning throughout the year.
The 49ers have a number of all-time greats in their history and it makes all sorts of sense to utilize them in some form or fashion. In this case, hopefully AJ Jenkins can take some time to learn from the greatest wide receiver of all time. There may never be another Jerry Rice, but that doesn't mean younger players can't at least learn from the GOAT.
In other news, Jenkins has indicated he will wear #17. He worse #8 at Illinois, but it is safe to say he will not be donning that jersey with the 49ers.