Joint-favourite Native River will not be competing at Aintree's showpiece in 2017.
Native River, the joint favourite for the Grand National, has been left off the list of entries for the race by trainer Colin Tizzard.
Having won the Welsh Grand National in December, Native River was thought to be certain of a place on 8 April but that has not proved to be the case.
The Last Samuri, who finished second behind Rule The World in 2016's race, is back for another shot at winning and is the favourite to win at 16/1, along with Grade One winner Don Poli, who is listed amongst trainer Gordon Elliot's 14 entries.
One for Arthur is also expected to be in the frame, having won the Betfred Classic at Warwick in January.
Much like the Gold Cup, the field for the Grand National will be smaller than last year, with 16 less entries than the 126 named for the 2016 race.
