ASM have seen off competition from Brentford to sign the young Brazilian.
Vanderson is already in the Principality to do a medical check after Grêmio accepted a €12m offer from ASM. The 20 year-old only made his first team debut a year ago.
UOL says the defender had verbally agreed personal terms with Brentford before ASM's intervention.
Vanderson could pen terms before the end of the week.
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