Lees has been a key player for Sheffield Wednesday since his 2014 switch from Leeds United.
Sheffield Wednesday signed Van Aken from Heerenveen in August.
Van Aken was partly to blame for Sheffield Wednesday's derby defeat on Sunday.
Sheffield Wednesday were linked with a move for the former Brentford defender before his move to Birmingham City, but signed Joost van Aken instead.
Sheffield Wednesday return to action against Nottingham Forest on Saturday.
Sheffield Wednesday return to action against Nottingham Forest this weekend.
Like Van Aken, Sibon also played for both Sheffield Wednesday and Heerenveen.
Sheffield Wednesday could be set for a busy last week of the summer transfer window.
Heerenveen defender Joost van Aken is in awe of Tottenham Hotspur defender Jan Vertonghen and Real Madrid’s Sergio Ramos.