The 18-year-old Legear, who plays in a withdrawn role behind the strikers, put pen to paper on a four-year deal until summer 2009. Russian starlet Guerk, 20, has been given two years with an option for one more.
The pair have so far been used sparingly, collecting 17 senior appearances between them last term. Legear has registered a solitary league goal while Guerk has yet to score.
The Brussels-based club have sent two more prospects out on loan for the season. Czech midfielder Martin Kolar, 21, and defender Gabriël Ngalula Mbuyi 'Junior', 23, will join English second-tier side Stoke City FC subject to medicals. Former Anderlecht coach Johann Boskamp is in charge at Stoke.
©UEFA.com 1998-2014. All rights reserved.