Rhinos’ 56-12 defeat in Cheshire was their worst loss for four years and came just a week before they face Australian champions North Queensland Cowboys in the World Club Challenge.
Leeds have a huge injury headache ahead of that game, with Tom Briscoe, Carl Ablett and Ashton Golding all suffering ankle damage and joining Danny McGuire, Stevie Ward, Jamie Jones-Buchanan and Beau Falloon on the casualty list.
“People would say it was a bad day at the office,” Hardaker said of the defeat two days ago.
“It was frustrating and a bit embarrassing as well at times.
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“It was difficult to take, but we have got to do something right because we’ve got a massive game this week.”
Rhinos were 16-0 down before Briscoe was hurt and they then lost Ablett and Golding in quick succession.
“That was massive,” Hardaker conceded. “We had three injuries in 10 minutes – Kallum [Watkins] went on to the wing, then I got pushed on to the wing and then Ashton went off and I went back to full-back.
“We were down to one substitute from then on in so it was always going to be tough, but with the team we’ve got I would still back us to come up with something better than we did.
“I can’t really put my finger on it and say that’s the reason why, we just weren’t good and they were really good.
“Some of the tries they scored were brilliant.
“They got some lucky ones to be honest, a bit of the bounce of the ball a few times, but they played really well and fully deserved the win.
“It is just disappointing with the scoreline, we should have been better there.
“We will have to look at the video to see where we went wrong and where we were all right in some areas.
“We defended all right sometimes, but it was not good enough at all. It was pretty poor.”
Hardaker was one of the few players to emerge from the game with credit.
He added: “I hate losing. I try to do my best to come up with things. When we are having an off day it is very difficult, but I have to try my hardest.
“Hopefully that showed. At least I can take some positives away from the game myself, but as a team, collectively, it wasn’t very good and for a big game coming up it’s not great preparation, but we will get it right.”
Of Sunday’s game, Hardaker said: “It is going to be difficult, but we’ve got quite a long week so that’s a positive. We will see what we need to correct.”
Head coach Brian McDermott, meanwhile, admitted: “All three of them are doubtful still and Ashton Golding was going to get near a bench spot anyway so it’s a real shame for him that he’s got a potential broken bone in his foot.
“Even if he hasn’t, the damage in his foot is significant enough. Carl Ablett and Tom Briscoe’s injuries are hard to tell yet - we’re not going to write them off yet but I wouldn’t put money on it.”