The 29-year-old finished last season on loan with the Blades and could now be with them for the start of the new Championship campaign.
Although Sunderland are understood to prefer a permanent deal for the ex-Gillingham man they have reluctantly agreed to sanction another loan as United cannot afford his fee or wages.
Nosworthy, who made 19 league starts for the South Yorkshire side last term, missed Gillingham's weekend 1-0 friendly success over Darlington to hold talks with the club.
"Nyron has travelled to Sheffield for talks over a possible loan move for next season," explained Black.
"That's the reason why he wasn't involved in our squad on Saturday.
"They have a long-standing interest in him and of course it's a club Nyron knows well."