Speaking to CBS Sports' Dennis Dodd, Allen offered a brief summation of what it's been like to work with Manziel as he prepares for the upcoming college season.
"Johnny has been very informative for me," Allen said. "Not just on the field but off the field, staying out of the spotlight, doing the right things."
In June 2016, the NFL suspended Manziel four games for violating the league's substance abuse policy. In March, NFL Network's Ian Rapoport reported the former Texas A&M star re-hired agent Erik Burkhardt with the hopes of making a comeback.
Rapoport and colleague Mike Garafolo added Manziel was "drawing real interest from teams" during the NFL Scouting Combine.
The 24-year-old Manziel last played in the NFL during the 2015 season with the Cleveland Browns. He started a total of eight games in two seasons, completing 57 percent of his passes with seven touchdowns and seven interceptions.