A jubilant Opie Bosson aboard Imperatriz. (Image: Trish Dunell)

Imperatriz (Image: Trish Dunell)

Walker: Imperatriz Te Akau's best

Trainer Mark Walker says superstar sprinter Imperatriz, who will attempt back-to-back Group 1 William Reid Stakes wins at The Valley on Saturday, is almost certainly 'the best horse Te Akau's ever had'.

Imperatriz is a nine-time winner at the elite level and had won six-successive races ahead of a rare recent defeat in the G1 Newmarket Handicap at her most recent start, but Walker is confident she can quickly put that result behind her on Saturday.

"She's bounced through that (defeat), she's got a clean vet bill of health and so we're looking forward to Saturday," said Walker, who decided against taking his stable star to The Valley earlier in the week.

"She just went across the road to the Cranbourne course proper; she went 1000m over there, in company.

"(Thursday) morning she travelled down to a local beach here and just had a morning in the surf, so she's bright and very well."

The return to The Valley, where she last year won the William Reid, G2 McEwen Stakes, G1 Moir Stakes and G1 Manikato Stakes, is another positive for Walker, who compared Imperatriz to a Mercedes.

"She just seems to camber when she turns for home, and changes onto that outside leg, I suppose it's like driving a Mercedes compared to a Mini, there's just that acceleration, isn't there," he said.

"She's certainly, probably, the best horse Te Akau's ever had now.

Unfazed by having drawn barrier 10 of 11, Walker and his Melbourne-based assistant Ben Gleeson also won't have to say too much to veteran hoop Opie Bosson, who is her regular rider.

"I don't think it's (the barrier) a problem, in the McEwen, first-up, she was back and even in the Moir, she was a fair way back, she's pretty versatile, I don't think it poses too much of a problem," he explained.

"Not a lot, I just sort of say, 'Give it a good warm up, ride it how you see it', so that's just standard. We've won a lot of big races over the years, keeping things simple."

As for the future beyond Saturday, Imperatriz is on target for a shot at the G1 T.J. Smith Stakes on April 6, while Walker also noted Moonee Valley Racing Club's announcement earlier this week of changes to its Spring Carnival timetable.

"I think it gives a lot of people a great set-up into The Everest, I think it's a very smart move, the sequence and the timing and the spacing of the races," he said.