Tidal Bay heads 58 entries left in the Coral Scottish National at Ayr following the latest six-day declaration stage.
Paul Nicholls' gelding, who unseated Sam Twiston-Davies in last weekend's Crabbie's Grand National having been badly hampered by Golan Way at the Canal Turn, is due to carry top-weight of 11st 12lb but the weights will rise 19lb if the 13-year-old misses the race.
Speaking on Monday, Nicholls said the race remained under consideration for his charge.
"He cantered as normal this morning and we'll make a decision later in the week about whether to let him run at Ayr," he said.
"The options are this or the bet365 Gold Cup at Sandown (April 26).
"It would be nice to get a steer on Sandown as I would probably run him there if the ground was good, but I'm a bit worried about it getting too quick.
"They caught him going past the stands (on Saturday), so he didn't do a lot."
Nicholls confirmed Sam Winner, second in the weights behind Tidal Bay, an intended runner in the big race.
Other notable confirmations include last year's winner Godsmejudge (10st 5lb), ante-post favourite Mendip Express (10st 7lb) and Battle Group (10st 7lb), who refused to start in last weekend's Crabbie's Grand National.
There are several notable absentees who also ran in the Grand National. They include Monbeg Dude, Walkon and Rocky Creek. Eider Chase winner Wyck Hill has also been scratched from the Ayr marathon.