Seabass is among a strong Irish entry of 31 for the Aintree spectacular on April 6 and has been set to carry 11st 2lb in the weights published today, with Lexus Chase hero Tidal Bay on top with 11st 10lb.
Tidal Bay has an official BHA handicap mark of 171, but has been rated as though he is 162 in the Grand National, for which weights compiler Phil Smith has discretion.
Walsh, speaking before seeing the full list of weights, said: "I don't know how Seabass can get over 11st this year if Tidal Bay is rated 171 and my horse is rated 154. Whatever Phil Smith does, he does, and I can't change it. You don't have to be a great mathematician to subtract 54 from 71."
Seabass returned to the racecourse for the first time since his gallant Aintree effort to run a staying-on second over two miles in a hurdle race at Fairyhouse last week.
Walsh went on: "Seabass will run somewhere in the next three weeks to a month. There is just over seven weeks to Liverpool so I would like to get a run into him. The Bobbyjo Chase at Naas and the Racing Plus Chase at Kempton are possible targets."
Walsh, who won the National in 2000 with Papillon, said of his other entry Colbert Station: "Like Seabass, Colbert Station will possibly have one more run. I have no idea where as he only recently ran. I would also be looking at running him in three weeks to a month, which will be ideal for the National."
The JP McManus-owned Colbert Station won a valuable handicap chase at Leopardstown over Christmas and followed up over hurdles at Punchestown, ridden on both occasions by Tony McCoy on testing ground.
Walsh said: "I wouldn't be worried about the ground for Colbert Station as it is never anything worse than good jumping ground at Aintree. He has 10st 6lb in the Racing Plus Chase at Kempton and is 3lb higher in England than he is in Ireland, which makes him worse off with Seabass in England."
Seabass was ridden by Walsh's daughter Katie last year, when she achieved the highest finishing place yet by a lady rider in the National. His son Ruby would appear to have a number of choices, while McCoy is retained rider for McManus.