within the Boro universe - or the Boroverse... Andy Campbell has gotta be up there.
Actually thinking about it, there are loads of boro examples. Matty Bates, Rhys Williams I had high hopes for, for example.
Alli definitely achieved more, he had a couple of very good seasons in the PL and then a good world cup, but Jeffers was seen as the next big thing and Arsenal paid a lot of money for him, about £9m I think. There was the belief that he'd go on and be England and Arsenal number 9 for the next 10 years.