The 22-year-old has had an impressive back end to the season at Hillsborough, after returning from his loan spell at Chesterfield, but he still has developing to do before he is the finished article.
Bullen feels that Lavery's final ball is currently lacking, but the Owls' coach loves the youngster's determined attitude and wants him to become the main man up front next term.
He said: “Whether he starts or comes off the bench, Caolan gives you that energy and there is an honesty to his game. He is willing to do his defensive and attacking duties. He is not shy of taking a shot and you have to have that ruthless streak as a striker. There will be times when Caolan will make a wrong decision but he is positive and doesn’t pass the buck.
“Hopefully this call-up will give Caolan an extra lift and he will comeback for pre-season training on July 1 full of confidence, well rested and wanting to show why he deserves to be our number one striker next season.”
Lavery actually appeared to be out of favour at Wednesday at the start of the campaign, but he has established his place in the first-team set-up now.
The Owls academy graduate scored twice in the final few games of Wednesday's season and will want to build on that showing next year.
If he is to become the side's main striker, then he will need to show a lot of improvement, though, as the role will carry a big responsibility.
Wednesday are among the favourites to be promoted next season and they will need to find a 20-goal a season striker from somewhere if they are to meet those expectations.