Vincent Kompany is an admirer of the teenage defender and has been looking to take him to Turf Moor during the ongoing transfer window.
Burnley lodged an offer of €1m with Anderlecht last week, but the Belgian side knocked it back as insufficient.
The Premier League new boys also have a four-year deal ready for Sadiki to sign, however with the bid rejected, they have placed the pursuit on hold, according to Belgian journalist Sacha Tavolieri.
Sadiki also has interest from other clubs.
Union SG would like to keep the defender in Belgium and have been talking to Anderlecht about a deal.
Anderlecht are looking for between €1.5m and €2m to cash in on Sadiki and Union SG could agree to pay it.
There is also interest in the young defender from the Netherlands, where Sparta Rotterdam and Fortuna Sittard have made enquiries about him.
