Nigel Twiston-Davies hopes patience will be rewarded for Blaklion when he runs in the Randox Health Grand National at Aintree on Saturday.

The nine-year-old looked the winner 12 months ago when Noel Fehily's partner gained the lead at the 26th fence, but his challenge petered out late on and he ended up finishing fourth.

He will this year be ridden by the trainer's son, Sam Twiston-Davies, with the Naunton handler keen for the jockey to delay his challenge a little longer than in 2017.

Twiston-Davies snr, who has won the race twice, said: "He'll be ridden with a little bit more restraint. He was only beaten eight lengths last year.

"I know he has gone up 8lb, but with a bit more restraint hopefully he'll be there."

Blaklion hardened as ante-post favourite for the Grand National after he won the Becher Chase at Aintree in December.

And though he was comprehensively defeated in a Grand National trial at Haydock in February, he has since undergone wind surgery.

Twiston-Davies' assistant Carl Llewellyn said: "He hasn't missed a day's work and we couldn't be happier with his physical condition - he looks really well.

"Some very good horses were pulled up at Haydock last time on ground that was very deep and holding.

"Blaklion had a lot of weight and I thought he ran a big race despite people picking holes in him because he got tired - I wouldn't let that performance at Haydock put me off him.

"He was impressive in the Becher Chase earlier this season. His jumping was superb and very accurate - he won as he liked. If he can be in that sort of form and jump as well as that, then hopefully he will have a good chance."

Twiston-Davies also gives Double Ross another chance to shine in the big race.

Llewellyn added: "He was running well in the 2016 National when the saddle slipped and looked to be taking to the track. Who knows what would have happened."

A strong Irish challenge is spearheaded by Total Recall, trained by Willie Mullins, and Tony Martin's Anibale Fly.

The former has long been considered a National hope by Mullins, but he did fall on his last start in the Cheltenham Gold Cup.

Patrick Mullins, assistant to his father, said: "Total Recall was running the race of his life when he came down in the Gold Cup and David Mullins felt he would have finished third at worst.

"That would suggest he's still ahead of the handicapper and he seems to have come out of the race fine.

"He has big-field handicap experience and a touch of class, too.

"If he gets luck in running he should give Paul Townend a very good ride."

The perennial Irish champion trainer also saddles Childrens List and Pleasant Company.

Mullins jnr added: "Pleasant Company was running an eyecatching race in last year's National until he made a mistake at Valentine's.

"He doesn't go there in the same form this year, but we're hoping he might rediscover his spark and if he does, he has to have an each-way chance.

"Childrens List beat Edwulf in his beginners' chase and if you take that form literally he's well handicapped.

"He has only had four chase runs and one point-to-point run, so he's inexperienced for a race like this, but if he gets a clear round you never know."

Anibale Fly produced a career-best when third in the Gold Cup and has been well backed in the build-up to the National.

Frank Berry, racing manager to owner JP McManus, said: "He ran a great race at Cheltenham and Tony is very happy with him."

Compatriot Tiger Roll is another leading candidate for Ireland, having won for a third time at the Cheltenham Festival in March.

Trainer Gordon Elliott is also responsible for Ucello Conti, running in the National for a third time, and the 13-year-old Bless The Wings.

Elliott, who won the National with Silver Birch in 2007, told Betfair: "We're running three but I suppose you'd have to say Tiger Roll is the main one.

"I think he's got a great profile going into the race. Davy Russell rides him and he's got 10st 12lb on his back, which is a lovely weight.

"Ucello Conti has been going very well at home and I think he'll run well. He (Bless The Wings) is not getting any younger, but he's been second in the Irish National twice. A bit better ground would have suited him."

Scotland ruled 12 months ago when One For Arthur won the National for Kinross handler Lucinda Russell.

Berwickshire trainer Sandy Thomson believes Seeyouatmidnight, who now runs in the colours of 1992 hero Party Politics, has a smashing chance of repeating the dose.

He said: "I'm feeling remarkably laid-back at the moment, although I found in my rugby days the nerves start to come on when you get closer to the event.

"We've been dealt the cards we've been dealt and I'm very happy with how the horse is.

"Conditions shouldn't affect him - they'll certainly affect other horses more - but it's the Grand National and anything can happen, which rather takes the pressure off a bit."