Austin said that a lot of Slay's troubles last year were due to the tough transition from college level, but remains confident that the youngster could follow the same route as Baltimore Ravens player Jimmy Smith.
"He needs to improve in a lot of areas, but a lot of it is growing pains," he told the club's official website. "I'll use an example of a guy I just coached, Jimmy Smith, who [Baltimore Ravens] drafted in the first round. Jimmy didn't become a full-time player until this year.
"He was a lot like Darius. He kind of flashed and has some tremendous talent. He would flash, but he didn't quite play as consistently as you'd like. But then he finally, like a lot of them, sometimes it just clicks. It takes reps it takes time and when it does, he starts improving in certain areas and everything else picks up."
Slay made 34 combined tackles in his debut season for the Lions.