You can do that without Admin. Create a specific, evenly enforced rule and Admin will back it.
1. If you win fewer than 60 games, the next season you must have $2M in unused Payroll all season
2. If you win fewer than 55 games, the next season you must have $5M in unused Payroll all season
3. If you win fewer than 50 games, you are not allowed to return
4. An owner in violation of 1 or 2 will not be allowed to return
We're trying a similar approach in Rickey to limit IFA signings of teams that miss the MWR. Don't know how effective it will be since it doesn't do anything about the draft, but we felt it was worth trying. Since Payroll is of limited value to a tanker, barring transfers to Prospects or limiting signing bonuses for IFA is probably more of a deterrent. You can enact anything you want as long as it's tied to a number (MWR, Budgets) and not using nebulous definitions such as "tanking" or "out of position."
The problem is approaches like that don't prevent someone from tanking his way to 60 wins.