Aberdeen have announced Ash Taylor, Tommie Hoban, Greg Leigh and Shay Logan will leave Pittodrie.
The Dons have issued a squad update following the conclusion of the season.
As well as Taylor, Hoban, Leigh and Logan departing loan players Florian Kamberi (St Gallen), Fraser Hornby (Stade de Reims) and Callum Hendry (St Johnstone) have returned to their respective parent clubs.
Right-back Logan joined Aberdeen on-loan from Brentford in January 2014 and was part of the side which won the League Cup a couple of months later.
The 33-year-old joined the Dons permanently in the summer of 2014, but after struggling for game time this season Logan was loaned to Hearts in January.
Centre-back Taylor, 30, arrived in the Granite City from Tranmere in the summer of 2014, he returned to England three years later to sign for Northampton before coming back to the Reds for a second stint in 2019.
Fellow centre-back Hoban signed for Aberdeen on loan from Watford during the 2018-19 season and suffered a cruciate ligament injury while playing for the Dons.
He was then released by the Hornets and after recovering from injury was signed permanently by Derek McInnes last summer.
Left-back Leigh spent the 2019-20 season on-loan at Pittodrie from Dutch outfit NAC Breda and returned to Aberdeen last October after leaving Breda, however, his appearances have been limited due to a hamstring injury.
Manager Stephen Glass “It is never an easy decision having to release players, many of whom who have a long association with the club over a number of years.
“But having had time to assess the squad in the latter part of the season, these decisions have been taken with our football strategy in mind, and to allow us to build a competitive first team for the season ahead.”