Trainer Kayley Woollacott admits she can find no reason for the seven-year-old's poor showing last week when he was pulled up in the Arkle - for which he was sent off a 13-2 shot.
Woollacott told her Betway blog: "Lalor's run in the Racing Post Arkle was obviously disappointing, because it was clear very early on that he wasn't going.
"For whatever reason, he just didn't fire. There's nothing wrong with him - we've been through everything and can't find anything. He's bucking and squealing at home."
Lalor has often appeared most at home on good ground, so the heavy rain which fell before racing on the opening day of the Festival was not in his favour.
However, his Devon trainer added: "We're not using the ground as an excuse. He wasn't travelling early in the race, so it couldn't have been the ground - and it was soft when he won at Aintree last year. We all know horses can have off days - it's just frustrating when you can't give a reason for a disappointing performance."
Nonetheless, Lalor will head next for the Grand National meeting - at which he has won for the last two years, in a Grade Two bumper and Grade One novices' hurdle, with the Maghull Novices' Chase his most obvious target.
"We'll just put a line through it and go to Aintree," said Woollacott. "At the start of the season, we always thought Aintree would be the main aim - because he's won there for the past two years.
"Obviously after the way he won (on chasing debut) at Cheltenham in November, we had to change our plans and decided to go for the Arkle. He's run very well both times at Aintree, and we're just hoping for some decent weather in the lead up to it.
"It would be lovely if we could get some nice ground and finish the season with a good run. I do think he's better on decent ground. We haven't lost any faith in him. We know he's a very good horse on his day and I hope we'll see that at Aintree."
