Steve Bruce hopes to agree a loan move for the England Under-21 starlet, but reports that Sir Alex Ferguson is prepared to listen to offers of around £8m for the 19-yearold have led to concerns that the Black Cats may be priced out of any potential deal.
The Sunderland manager is not prepared to splash a large chunk of his transfer kitty on a player unproven at Premier League level.
Bruce's spending on new players has been relatively low key this summer with the majority of his funds being kept back to strengthen his defensive ranks. Manchester City utility player Nedum Onuoha remains a target although German centreback Heiko Westerman is close to agreeing a £6m move from Schalke to Hamburg.
The deal for Welbeck is unlikely to be completed until Man United return on August 1 from a pre-season tournament in the United States, but Ferguson will consider sending some his talented youngsters on loan to further their career.
We've a fine collection of young players who, if you don't give them an opportunity, are going to stagnate and move to other clubs who'll get the benefit of the work we've done with them.
We've had experience of that, so we try to that as best we can make the right decisions about these boys' careers because most of them are very good, talented players, said the Man United boss who saw Welbeck score in the Red Devils' 3-1 friendly victory over Celtic last Saturday.
Campbell urged Bruce to make Welbeck the latest recruit to swap Old Tradfford for the Stadium of Light.
I know Danny really well.
He is a good lad and a very good young player, said Campbell.
It would be nice to see him up here. He is skilful, sharp, quick and scores goals. He is a good young professional and could do a good job for us.
We are turning in to Man United's reserve team with all the lads coming from there to Sunderland! I keep in touch with Danny. I've not spoken to him in the last couple of weeks but I would definitely say to him get yourself up here.
Sunderland continue their pre-season campaign this evening when they face Brighton in the Estadio Municipal, Albufeira, Portgual (kick-off 7.30).
Andy Reid had an injection on his troublesome Achilles on Monday before jetting out to join the Black Cats Portuguese training camp but Marton Fulop, David Healy and Teemu Tainio who played in the reserve side at Berwick last night, will continue their preparations on Wearside.