The decision by the Court of Arbitration for Sport to suspend 12 current Essendon players for taking a banned drug has forced the AFL to again unveil contingency plans, as was the case last summer when players were provisionally suspended.

The Bombers are now widely tipped to finish near or at the foot of the ladder, at least handing the club a high draft pick, but hopes of making the finals in the first year under new coach John Worsfold have been dashed with skipper Jobe Watson, vice-captain Dyson Heppell, key defender Michael Hurley and last year's best and fairest Cale Hooker among those outed.

In a bid to minimise the impact of the suspensions, the AFL will allow the Bombers to upgrade their five rookie-listed players as replacements, as though the suspended players had long-term injuries.

The Bombers can add 10 top-up players, not limited to previous AFL players, with AFL boss Gillon McLachlan adding existing salaries for the listed players who have been suspended will be included under the salary cap.

Added payments to supplementary players will be included in the club's salary cap but the Bombers will receive an allowance for payments to supplementary players over the cap limit.

The Bombers said they would cast a wide net when looking for talent in second-tier competitions, and did not rule out contacting recently retired AFL players.

The four other clubs also impacted by the CAS ruling - Port Adelaide, Melbourne, St Kilda and the Western Bulldogs - will each be able to upgrade one rookie to their senior lists as a replacement player.

The Saints have lost star recruit Jake Carlisle, who had already found himself in trouble late last year when he took illegal drugs and simultaneously filmed himself, while the Bulldogs will be without forward Stewart Crameri. The Demons won't have recruit Jake Melksham, while the Power have lost Angus Monfries and Paddy Ryder.

Bombers chairman Lindsay Tanner said the club was "now entering one of the most challenging periods in our history".

McLachlan said the Bombers would be "weakened" but would still retain their right to face Collingwood on Anzac Day in the biggest home-and-away clash of the season.

He said league counsel Andrew Dillon would seek answers this week as to what contact the suspended players could have with their clubs this year.

Player agents were also seeking answers as to whether their clients would be allowed to profit in any way from the sport, such as having a media role on match days.

The Bombers open their home-and-away campaign against the Gold Coast Suns at Metricon Stadium on March 26 and then face a rebuilding Melbourne at the MCG. Tougher assignments against Port Adelaide, Geelong and Collingwood then await.

"The AFL will support the players and the club through this period but these suspensions must stand as part of our commitment to clean sport," McLachlan said.

AFL chairman Mike Fitzpatrick said the drugs saga "will not define the Essendon Football Club".

"It will not define Australian football. Essendon's history is too important … and its future is owned by the members and supporters, and not by the last four years," he said.

"The club has two very respected people in the new chairman, Lindsay Tanner, and new coach, John Worsfold, and the AFL is committed to doing what we can to assist the club in moving forward."