Brighton have had a £2m bid rejected by Sunderland for midfielder Paddy McNair, Sky Sports News understands.
The 23-year-old made 18 appearances, scoring five goals, as Sunderland were relegated from the Championship last season.
McNair moved to the Stadium of Light in 2016 after coming through the youth system at Manchester United.
The Northern Ireland international broke into Manchester United's first team in 2014, making 24 Premier League appearances.
He made his international debut in 2015 and was part of Michael O'Neill's squad that reached the round of 16 at Euro 2016.
Brighton have already signed Nigeria international defender Leon Balogun on a free transfer from German side Mainz, as well as agreeing a deal with Deportivo for Romanian forward Florin Andone.
They have also made a bid for Reading defender Liam Moore, according to Sky sources.