Jelavic has been a revelation since his arrival in January.
"Once you get the players, it's how to man-manage them and David has been excellent at doing that and getting the best out of players," said the Well boss. "I was at Finch Farm last week on a [UEFA] Pro Licence course and David's thirst for work and his energy and enthusiasm shone through. He's done an outstanding job and he keeps picking up these players who he moulds into Everton players and then gets the best out of them.
"Phil Jagielka, who I worked with at Sheffield United, I was delighted when they took him because I thought Phil had all the attributes to make that step up. Mikel Arteta earlier on before that. He's bought people not at top dollar if you like, without spending millions of pounds. And now, in Jelavic, it looks like he's unearthed another one."