The Italy international spent last season at the Stadium of Light, gaining hero status for the part he played in their late escape from relegation and run to the Capital One Cup Final – a game in which he scored against Manchester City.
Since then Gus Poyet has been keen to get him back to the North East, with a £14m offer submitted a number of weeks ago still on the table.
Liverpool are understood to be ready to let the versatile forward leave, but the player himself is not so open.
Even with the arrival of Mario Balotelli at Anfield, Borini is ready to fight for his future on Merseyside, and does not want to leave just yet.
However he is ready to go on loan with a view to gaining more top-level experience ahead of a return to the club.
Liverpool may sanction the deal to reduce their spending on wages, while Sunderland are likely to be keen with Poyet a big fan of the goal-getter.