Sunderland head coach Gus Poyet is said to be eager to take the 24-year-old to the Stadium of Light, having worked with him during his time at Brighton, but has remained tight-lipped on any pursuit of the 24-year-old.
Buckley played no part in the Championship club's League Cup first round victory over Cheltenham Town on Tuesday, leading to more questions over his future.
Brighton boss Hyypia revealed that it will soon come to light why the former Watford man was omitted from his squad, with Sunderland reportedly preparing a £3 million bid to take him to the north east.
"He wasn't available for selection." said the former Liverpool and Finland defender.
"I think you'll hear it in a few days."
One winger on his way out of the Premier League club is David Moberg Karlsson after the 20-year-old Swede joined FC Nordsjaelland for an undisclosed fee.
Nordsjaelland, who joined Sunderland from IFK Gothenburg last year, has signed a four-year deal with the Danish club.
