The Dutchman, 19, is the youngest foreign player in the Hero Indian Super League and was the first goal scorer for his former team in this season of the ISL.
The youngster already has four goals and an assist in the tournament and will be looking to add to that tally with the Gaurs who are the highest goal scorers of the tournament, having played only 10 games.
Sifneos also scored a goal against the Gaurs when Kerala played Goa at the Jawaharlal Nehru Stadium in Fatorda.
"The club is pleased to get Sifneos on board. He's a player who has already proved his quality in the league this year with his goals and all round play. We hope he can continue to replicate those performances for us," said an FC Goa official.
The Dutchman has been signed as a replacement for Spanish striker Adrian Colunga who was released recently.