Key, who finished second in the SEC in sacks last season, missed spring practice for personal reasons and is recovering from shoulder surgery.
"We don't know when he'll be back," Orgeron said, declining to go into the specifics of Key's absence during the spring. "But we expect him to be back and have a great season."
Not only that, Orgeron called Key one of the best defensive players in the country and said he could rival the productivity of former Texas A&M star and 2017 No. 1 overall pick Myles Garrett.
"Can Arden Key reach that status and perhaps surpass that?" Orgeron said. "Yes, he can."
Key, who was a Freshman All-American and SEC All-Freshman choice in 2015, has 17 sacks in two seasons as a defensive end/outside linebacker.
ESPN NFL draft expert Mel Kiper Jr. projects Key as one of the top 10 draft-eligible prospects in 2018.