William Alves came to AS Trenčín in winter 2012–13 and signed a three-and-a-half-year contract. He made his debut for AS Trenčín in a friendly match against Czech SFC Opava on 26 January 2013. On 2 March 2013, he made his competitive debut for Trenčín in the league game against Spartak Myjava, when he came on in 77th minute. In winter 2013–14, he left the club due to a disagreement between AS Trenčín and Botafogo.