Why not? Have a new online mode called "Big Ant Championship Team" mode where users can only play with the players they draft... and if they are not happy with the cards/players dealt them, they can "upgrade" to a better plyer or sets of players by dishing out extra cash. $1.99 per player gets them a Level 3 player (say Bailey), $2.49 gets them a Level 2 player (say Bravo) and $3.99 gets them a Level 1 player (say Root or Kohli). Of course if the user is willing to shell out $12.99 for a Level 2 pack he/she gets a team full of random Level 2 players and $24.99 Level 1 pack gets them a team of Level 1 players.
Maybe Big Ant can also link XP points to this mode so if you have 5000 XPs you can buy a Level 2 player and for 10000 XPs you can buy a Level 1 player. This way Big Ant can claim you don't have to purchase players with cash. And the rest of us can play with Academy created players in offline and online H2H (Head to Head) modes