Sunderland's Paddy McNair played in 24 Premier League games for Manchester United
Sunderland have accepted an offer from Middlesbrough for Northern Ireland defender Paddy McNair in a deal that could rise to more than £5m.
The Black Cats, relegated to League One, are resigned to losing McNair, 23, who joined from Manchester United in a joint deal with Donald Love in 2016.
BBC Sport understands personal terms are being discussed.
Premier League Brighton had two bids for the player turned down and are now looking at other targets.
Find all the latest football transfers on our dedicated page.
Source: bbc.com