Sunderland are reportedly lining up summer bids for Victor Moses and Steven Fletcher.
Moses recently told Wigan Athletic that he would not be signing a new deal with the club, while Fletcher's future is uncertain following Wolverhampton Wanderers' relegation from the Premier League.
However, Black Cats boss Martin O'Neill has been told that he must sell before he buys, according to the Express.
That could open the door for winger Stephane Sessegnon to leave the Stadium of Light at the end of the season.
The Benin playmaker has been linked with a number of the league's top sides.