The Baggies boss was delighted with the Bosman free transfer capture of Argentinian midfielder, Yacob, from Racing Club de Avellaneda in his homeland given that he was a virtual unknown in England.
Yacob picked up the man-of-the-match award in his Premier League debut game against Liverpool and never looked back as he has become a mainstay of the Albion side over the past campaign.
The challenge now is for the club to find more players in the same mould as Yacob and sign them up before their Premier League rivals can pounce. And Clarke is backing his scouts to come up trumps for him once again.
He told the club's website: "The secret is not looking in different places; the secret is finding the right player. It doesn't matter where you look.
"Sometimes they're under your nose and sometimes they are a little bit further away.
"But the secret is always to find the right player and, I think, by and large, with the boys we got in last season, we found the right players."