The time has arrived for Jarrod McLean to test Cougar Express at the highest level.

The Warrnambool trainer has kept Cougar Express away from the better performed jumpers in the lead-up to Sunday's $250,000 Grand National Hurdle at Sandown.

After three hurdle runs towards the end of last year's jumps season, Cougar Express returned to hurdling with a maiden win at Warrnambool's May carnival, carrying that form to victories at Casterton and Morphettville.

McLean said the National was a target from the outset of Cougar Express' campaign but his last-start fourth at Morphettville, as odds-on favourite, left McLean deflated.

"I've gone down a little bit of a different path in trying to dodge the better horses by bypassing the Lafferty (at Warrnambool) and the Brendan Dreschler (at Bendigo)," McLean said.

"We thought we'd go to Adelaide and he'd win, but he made a couple of mistakes and ran fourth.

"That wasn't part of the plan."

McLean sees unbeaten hurdler, topweight Self Sense, as a stumbling block.

"Realistically we need Self Sense to be making an error to be beating him," McLean said.

"He's talked up as one of the better hurdlers we've seen in a long time and rightly so, but it's a jumps race and anything can happen.

"You only have to hit one hard as we saw with Cougar Express last start and it evens things up."

After his disappointing display at Morphettville McLean intended to school Cougar Express over bigger obstacles in a bid to treat his jumps with more respect.

But he abandoned a trip to Cranbourne last week while the steeplechase lane used for schooling at Warrnambool was too heavy.

"We popped him over a few hurdles instead and he's good to go," McLean said.

Self Sense is the $2 favourite to continue his unbeaten run over hurdles while Cougar Express sits on the third line at $9.50.

Top class jumper Wells is aiming for back-to-back wins in the day's other feature, the Crisp Steeplechase.

Wells will carry 70kg on Sunday in the set-weights and penalties affair, the same as he did last year ahead of lumping 71.5kg to win a third Grand National Steeplechase last August.