ESPN's Adam Schefter first reported the diagnosis. The Jaguars selected Fowler, a defensive end who attended Florida, with the No. 3 pick in this year's draft.
Fowler went down clutching his left knee after rushing at an offensive lineman. He was helped off the field after trainers examined him and transported on a cart to EverBank Field.
According to Schefter, Fowler signed an injury protection waiver before the injury that "obligates Jaguars to negotiate in good faith." Fox Sports' Mike Garafolo reports that the DE is in line for a four-year, $23.5 million deal that's fully guaranteed.
Video of the sequence is embedded below.
In 12 games with the Gators last season, Fowler recorded 60 tackles, 15 tackles for loss and 8.5 sacks while helping Florida rank first in the SEC in yards allowed per play.