	Maroši started out at Sigma Olomouc in 1987. Olomouc achieved third-place finishes in the Czechoslovak First League in 1990–91 and 1991–92 and subsequently qualified twice for the UEFA Cup. In the 1991–92 UEFA Cup, Maroši scored in the second round match against Torpedo Moscow and Olomouc went on to reach the quarter finals.