Костшин-над-Одрой
Fabiański was born in Kostrzyn nad Odrą, Lubusz Voivodeship. After starting his career with Polonia Słubice, Fabiański joined the noted independent football academy MSP Szamotuły at age 14, where he honed his footballing skills. Fabiański then was signed in the 2004–05 season by Lech Poznań.