Patriots backs put in 'passing camp' work: White impressive, Burkhead adjusting

FOXBORO — The running back position has been one of the fascinating to watch on the Patriots roster this spring and that shouldn't change as the team transitions to training camp later this summer when pads are introduced.  It's a deep group. Adding Mike Gillislee and Rex Burkhead to Dion Lewis, James White and second-year back DJ Foster provided the group a measure of insurance that it hasn't had in recent memory.  Though it's difficult to get a true sense for how backs stack up when all players are clad in shorts and t-shirts, here's a quick rundown of what we saw from each member of the running back room during three days of minicamp this week . . . DION LEWIS It was an abrupt end to a bumpy