The stricken full-back was helped off with just three minutes remaining of Saturday’s stunning 53-10 success which set up a quarter-final meeting at holders Hull FC next month.
His injury was the only sour point for Daryl Powell’s side following another glorious display but – despite his initial fears – Hardaker believes he will actually be fit to face parent club Leeds Rhinos at Magic Weekend on Sunday.
Hardaker told The Yorkshire Post: “I heard a crack initially as soon as I did it.
“My ankle just got caught underneath but I think I scared myself more than anything with what I’d done.
“It’s not too bad. It’s all checked out alright and with a few days resting it up should be ok.
“We’ve landed okay with the turnaround as well; if we were playing Leeds on Friday it might have been pushing it a bit but, hopefully, I’ll be alright for Sunday.”
The derby rivals bring a close to Magic Weekend in Newcastle with what should be the game of the festival.
Castleford vanquished their illustrious neighbours 66-10 the last time they met at Wheldon Road at the start of March, perhaps the first hint that Daryl Powell’s side could be building something impressive at Wheldon Road this term.
They have continued as the most exhilarating – and consistent – side in the competition but traditional giants Leeds, too, have strung some form together and are just two points adrift of the league leaders as the competition reaches its midway point.
Hardaker won three Grand Finals with Rhinos and two Challenge Cups but is on a season-long loan at Castleford where he is beginning to rediscover the sort of form that earned him the 2015 Man of Steel.
“It should be a cracker,” he said. “When the fixture came out and we saw we had Leeds at Magic it was always going to be tasty.
“Leeds v Cas games always are but especially Sunday as the atmosphere should be cracking.
“We’re the last game and hopefully all fans from the games before will stick around.
“I’m pretty sure they will do as these are two exciting teams; attacking wise both are really, really good and at the moment our defence is really good too so it’s all making up for a cracking fixture.”
Castleford are winning fans from inside and outside of the sport with the style and grace of their football at the moment, Powell’s side seemingly able to cut any opponent to shreds.
Asked what it is like to play in such a free-flowing, expressive side, Hardaker responded: “It’s just brilliant.”
“Greg (Eden) scored a try in the corner on Saturday and walking back he said “I just love it when we play like that.’
“I agreed. A few weeks before when we played Wigan down here we started really well against them, too, and blew them off the park.
“As soon as we start playing with that confidence flowing into us I think it is a bit unstoppable. At this moment in time it is brilliant.”
There was clearly no negative effects on Castleford either after a trio of their players – Hardaker, scrum-half Luke Gale and second-row Mike McMeeken – returned quickly from the previous week’s England win against Samoa in Sydney.
“The funny thing is before we went the staff at Cas were saying ‘It’ll be a bit of a break for you over there,” added Hardaker.
“I thought did they realise it was Samoa we we were playing, a really good team!?
“But I played centre so I didn’t get as much ball or run as much as I normally do so I reckon, if anything, I recovered more from the Samoa game that Saturday than I would have done if I’d have played Huddersfield with Cas the Thursday before.
“I came back rejuvenated and it just shows as Galey got man-of-the-match against Saints, Mikey did pretty well, too, and we did the job.”
The 25-year-old admitted he was as surprised as anyone when England coach Wayne Bennett picked him out of position at centre against Samoa despite him shining in his usual position for the Super League leaders this term.
“I didn’t know I was going to play centre,” he said. “I got there and I’m not sure why; it’s Wayne.
“He asked me if I wouldn’t mind playing it and I said ‘look, I’d play anywhere.’ I’ve done that since I was seven years old.
“I don’t know why he went with me but he did do and it was a fantastic trip.”