AP McCoy's expected mount in his last Grand National, Shutthefrontdoor, has been allotted a weight of 11st 2lbs for the handicap at Aintree on 11 April.
The 19-times champion jump jockey announced earlier this month he will retire by the end of the season.
Shutthefrontdoor, owned by JP McManus and trained by Jonjo O'Neill, is favourite despite not having raced since a win at Carlisle in November.
McCoy will ride his 20th National and won it on Don't Push It in 2010.
He also had the option of riding Carlingford Lough but the Irish Hennessy winner is now unlikely to run after being given top weight 11st 10lbs for the race.
Trainer John Kiely said: "The owner (JP McManus) and Frank Berry (his racing manager) will decide but I don't think it would be likely he'd run. The Gold Cup is his main aim and the horse is in good form."
|The weighting game|
|Allocation of weights is a pivotal moment for trainers, jockeys, owners and punters.|
|Unlike the Cheltenham Gold Cup, where horses race off level weights, the Grand National is a handicap.|
|Horses are ranked according to their previous form, with the best given top weight.|
|The handicapper's ultimate (although in practice unfeasible) aim is for the horses to pass the winning post in a dead heat.|
|The closest finish came in 2012 when Neptune Collonges denied Sunnyhillboy by the shortest possible distance - a nose.|