The AFL has ruled that Port Adelaide, St Kilda, Western Bulldogs and Melbourne will not be permitted - as Essendon have been - to contract replacements to cover for their losses.

Essendon were  permitted to sign up to 10 top-up players to cover for the 12 who had been banned for the year by the Court of Arbitration for Sport.

The AFL canvassed the remaining AFL clubs for their view of the bid by the four clubs to be given access to replacements. The clubs varied from the stridently opposed to those who didn't care.

The large number of suspended players at Essendon made their situation different as they would not have been able to field a competitive team without the replacement players whereas one and two players suspended at other clubs was seen to be little different to a club missing a player through injury or, for instance, GWS losing Cam McCarthy through homesickness.

Port Adelaide had argued for two replacement players to cover the losses of Paddy Ryder and Angus Monfries but also reasoned that at worst they should receive access to one player. Ryder was already facing drugs charges when he arrived at the club whereas Monfries was recruited before infringement notices were issued.

Port Adelaide chairman David Koch said the club was disappointed but would accept the AFL's decision.

"Obviously we're disappointed because clearly we are an innocent victim in this saga and we thought we put together a compelling argument to the AFL," he said.

"However, the AFL saw it differently and we will now abide by their decision and get on with the task at hand.

"Today's outcome will not define our season and win, lose or draw it will not serve as an excuse as to how we perform on-field."

Essendon have so far signed seven top-up players and are poised to add former Hawk forward Sam Grimley while ex-Brisbane ruck/forward Sam Michael has trained with the Bombers this week so the club can look at him before deciding  whether to add him to the list.

Michael, 22, is a 199-centimetre ruck who played three games for Brisbane in 2013 after being recruited as a Queensland rookie.

The Bombers are eager to add a key defender but have struggled to identify suitable candidates at the state league level or among willing recent retirees. Brian Lake would have been an ideal candidate but he was unwilling to come out of retirement.

Essendon might only decide to pick up nine players, rather than the 10 allowed, on short-term contracts to cover the suspended players.

The club expects  it will cost it at least $1.5 million in payments to the top-up players as well as additional match payments for existing players who will play more matches  than they would  had the core of senior players - who are on large base-only contracts - been playing.

Michael Gleeson