Cowan is expected to be back early next week.
Cowan was one of three unanimous selections to the team.
The Terps will play home-and-home series against Iowa, Ohio State, Illinois, Indiana, Northwestern, Rutgers and Michigan State.
The duo is one of the most talented in the country, with Katz believing both players are elite.
Cowan led the Terps with 15.6 points per game last year.
Fernando averaged 13.6 points and 10.6 rebounds per game in his sophomore campaign.
The Terps' top-two scorers plan to hire agents but can still return.
The forward had a standout NCAA tournament.