Republic of Ireland defender Richard Dunne was among a number of players released by Aston Villa on Wednesday, the Premier League club announced.
Dunne, who joined Villa from Manchester City in 2009, will leave the club when his contract expires, along with Cameroon international midfielder Jean Makoun, American defender Eric Lichaj, and veteran English goalkeeper Andy Marshall.
Makoun spent the season on loan at French club Rennes and will join the Ligue 1 side on a permanent basis on July 1.
Dunne, 33, did not play for Villa once this season due to injury and had to wait until the closing stages of Ireland's 4-0 friendly win over Georgia on Sunday to make his first appearance since June last year.
However, Celtic manager Neil Lennon has expressed an interest in signing him, telling Scottish newspaper the Daily Record that the imposing centre-back was "a player I have known a long time and have always liked".
Meanwhile, attacking midfielder Simon Dawkins will return to parent club Tottenham Hotspur after a loan spell at Villa Park.