Thoolen, 18, came to the club at pick 47 in last year's draft, but failed to play a senior game and spent 2008 playing in the VFL.
The former Bendigo Pioneer joins Sam Iles, Chris Egan and Brodie Holland as Magpies to be moved on ahead of next season.
In further changes at the Lexus Centre, Sharrod Wellingham and Brent Macaffer have been elevated from rookie status to the senior list.
Both players were second year rookies in 2008, but spent time on the senior list with Wellingham gaining promotion for Brad Dick and Macaffer for Sean Rusling.
Wellingham played 12 senior games for the year after debuting on Anzac Day against Essendon, but Macaffer didn't make it into the firsts, playing in the reserves and jointly winning the club's best VFL player award for his efforts.
Rookie Luke Casey-Leigh has also been let go by the club after one year on the list.
Former New South Wales scholarship holder Scott Reed will join the club as a NSW-rookie listed player, while Queenslander Lachlan Keeffe will be officially placed on the rookie list after signing with the Pies as a pre-selected rookie last year.
The retirements of Scott Burns, Shane Wakelin and Ryan Lonie, and the trading of Rhyce Shaw to the Sydney Swans make up the departures from Collingwood so far.
The Magpies have welcomed former Brisbane Lion Anthony Corrie to the club as a result of trade week, with the young defender to join his teammates in the coming weeks.
Collingwood will have five picks in the November 29 NAB AFL national draft – 11, 29, 45, 46 and 77.
