Wow.
If you can't think of any, doesn't mean that it didn't happen, so what was your point to begin with.
It has been proven and said by many experts since the 70's. It often takes any WR no matter what round, several years or more to adapt.
Hence, Tom Landry's 3 year rule on players. Reiterated by Bill Parcels and others.
Granted players coming out of college now are better prepared to make contributions right away. However, Tolbert is from a small school with lesser coaching than what Lamb, or Chase or Jefferson had.
I am not defending Tolbert, just saying he may need more time. I am willing to wait to see any progress.