Kilmarnock welcome aboard Portuguese winger
The 23-year-old, who had been on trial at Killie after being released by Bulgarian side CSKA Sofia last month, has signed a two-year deal.
"Silva plays wide midfield and he's very skilful and sharp and will add to our squad," the Finn told the Sunday Mail.
"We're looking forward to seeing him play in the SPL but it always takes a little while for players to adjust to the pace of the game when they move to a different country.
"Will the supporters like him? Fans like any player who does well so it depends on what he produces on the park but hopefully he will settle quickly and do well."
Paatelainen is hoping to add more faces to squad before the transfer window closes on August 31.
He added: "It doesn't stop here and we will continue looking for other players.
"There are a number of positions we are looking to strengthen."