The Croatia international moved to Goodison Park from Rangers on transfer deadline day last January and made a flying start to life in a blue shirt.
The 27-year-old struck 11 goals in 16 games as Everton finished the 2011/12 strongly, eventually securing a seventh place finish in the Premier League.
This year the former Rapid Vienna frontman has found life a little tougher, scoring five goals in 15 appearances across all competitions, but with just one of those coming in his last eight matches.
Belgium star Marouane Fellaini has been pushed further forward by boss David Moyes this season, playing just behind Jelavic, and he has responded by scoring eight goals in 14 games.
Jelavic believes Fellaini's joy and Jelavic's woe is a prime example of how form can come and go in football and he has backed Jelavic to come good.
"Everything was working for him when he came and now the person who is playing up front with him - Felli - everything is coming off for him," he told the club's official website.
"Look up at Newcastle, Demba Ba was on fire then Papiss Cisse came and Ba didn't score. This season it is the opposite way round, that is the way cycles go.
"He knows we're supporting him and he'll get frustrated on the days it doesn't happen but we know he'll come good. And, at the moment we're doing okay without his goals so when he does hit the ground running again he'll make us even stronger."
Moyes' side take on fourth placed Spurs at Goodison Park on Sunday having seen the London club leapfrog them in the table following three successive wins.
Jagielka is all too aware of the task facing his side against Andre Villas-Boas' in-form team, but given the Toffees have not lost at home since March, he is confident they will give the Londoners a tough match.
"We have done well at Goodison this year and we want to make it a hard place to come," added the former Sheffield United man.
"It is going to be difficult, Spurs are free-scoring at the moment and keeping clean sheets but they have not had the best of runs when they have come to Goodison before and we want to make sure they go home at the weekend with a similar feeling."