Celtic have accepted a bid of around £2m from Sunderland for defender Adam Matthews.
The 23-year-old Wales international could complete a switch to the Stadium of Light on Friday if he agrees personal terms.
Celtic agreed to let him go after securing the services of fellow right-back Saidy Janko from Manchester Utd.
Matthews joined Celtic from Cardiff City in 2011 and has made 148 appearances for the Glasgow club.
He played 42 times as Ronny Deila's side retained the Scottish Premiership title last season.
Matthews, who has 12 caps for his country, has also played on the right of midfield at times for Celtic.