Dingo Dollar will complete his Randox Grand National preparations with an outing at Doncaster on Wednesday.

The 10-year-old, currently a general 50-1 chance for the Aintree feature, lines up in the Virgin Bet Veterans' Handicap Chase on what will be his first start since finishing third in a strong renewal of the Rehearsal Chase at Newcastle in November.

Dingo Dollar is currently rated 148 and should make the cut for the National with ease and trainer Sandy Thomson admits he was keen to protect that mark.

"That will be his prep-run for the National," said Thomson.

"We are looking forward to that. We didn't dare run him before that to save his weight.

"The ground is not ideal, but he will get a run and then it is all systems go to Aintree."

Dingo Dollar will face five rivals at Doncaster, including Vintage Clouds and Black Op.

While Thomson has no concerns about Dingo Dollar making the Aintree line-up, he admitted his frustration that narrow Becher Chase runner-up Hill Sixteen will likely miss out.

He was beaten just a nose by Snow Leopardess over the National fences in December, but while the winner is a 14-1 chance and reasonably well-placed on the list at this point, Hill Sixteen sits well outside the top 40 on a mark of 138 after pulling up in the Welsh National and finishing fourth in the Sky Bet Chase last time.

"Unfortunately, it seems the Grand National qualification is totally ridiculous, as far as I am concerned," said Thomson.

"You get something like Hill Sixteen that runs in the Becher and you just get beaten by a horse that is the top British challenger for the National, and he can't get into the National.

"They need to start making a qualification procedure, and need to look at having some qualifying races, so these thorough stayers who will be ideally suited to Aintree get a chance to get in."

While Aintree appears to be off the table, a National bid is still in prospect for Hill Sixteen.

"The Scottish National is probably the long-term plan for him," confirmed Thomson.

"Whether he goes to the Grimthorpe Chase before that, I'm not really sure.

"He ran a hell of a race at Doncaster the last day on ground that was far too quick for him. The way the ground is at the moment, at Doncaster, over another two furlongs on softer ground, maybe he goes for the Grimthorpe."