Jeffrey has booted eight goals from five matches for the Queensland club this year, including a five-goal haul against the Western Bulldogs in Round 10.
That performance saw the Drawin product earn a Rising Star nomination, having also amassed 10 disposals, five marks and two contested marks in the loss.
The 20-year-old has booted majors in each of his last four appearances this year, complimenting Dew's new-look attack that has been led by tall duo Mabior Chol and Levi Casboult, and lively small forward Izak Rankine.
A sombre Dew revealed to AFL.com.au that Jeffrey will be sidelined for the remainder of the season as the club takes a conservative approach with the forward's recovery.
"It's really unfortunate," Dew said on Thursday.
"Joel was adding something to our side and getting comfortable at the level.
"It's one we were really surprised by given it wasn't too sore (after the game) … but when he walked in on Monday hobbling my heart sank a bit because I was just disappointed for him because he's done a lot of work to get to where he is.
"You just want your young lads playing."
Jeffrey made his debut for the Suns last season against Melbourne and played out the final four matches of club's season.
He joined Gold Coast as an Academy selection from the Northern Territory through the 2020 National Draft.