The six-year-old has recorded successive second placings over 1400m at Warwick Farm and it was after her latest, two weeks ago when narrowly beaten by Running Bear, Dean Mirfin saw an opportunity and sees no reason why she won't hold her form in the Furphy Handicap (1600m).
Mirfin and Reece Jones, who is coming off a Group 2 win last weekend, will also combine in Saturday's $500,000 Newhaven Park Country Championships Final with De Forerunner after he secured a last minute place in the field when fellow Bathurst galloper Possibly So was ruled out with injury.
"I spoke to Reece after (Whatsin) ran the other day about stepping up to the mile and he said that would really suit her,'' he said.
"We've got the right kind of race, it's a fortnight between runs again, and she's in good order and likes the sting out of the ground.
"It's worth a go, I think she is suited to 1400m where there's speed on and she can hit the line but I'll take Reece's advice on board so if we are ever going to have another go at a mile this is the time.
"I think she will run it. He's a good judge so we'll take his word."
Whatsin, $7.50 with TAB on Tuesday, has raced twice at 1600m and once at 1800m and performed below expectation but Mirfin believes the form she's racing in at present warrants another shot.
Particularly given the way she's returned in 2023, kicking off with a win and progressing to her recent city placings.
"She's always looked type wise like a big miler. She's always had ability, probably the nicest type of mare I've ever had,'' he said.
"Last time in she was a little inconsistent, she had hormonal issues and she just didn't seem right. She's come back from a spell this time in and just looks better and she's racing in the best heart of her life."
Mirfin said he feels for connections of Possibly So after Andrew Ryan's gelding was ruled out of Saturday's Country Championships Final but is also pleased he kept De Forerunner in work after the Central Districts Championships on February 19.
De Forerunner finished third in that race, so as first emergency for the region gains a start, and has since run a close fifth at Hawkesbury. He'll be Mirfin's fourth runner in the Randwick feature.
"It's great to have a runner in the Final but I feel sorry for Andy. It's bittersweet,'' he said.
"My immediate thought was to give the horses that went to the race a break but he ran third and I thought we better keep ticking over in case something happens.
"We took him to Hawkesbury and he didn't get beaten far.
"I'm under no illusion, winning a Country Championship Final is a very difficult assignment but he's got no chance of winning it if he's at home in his box."