Manly skipper Jamie Lyon agreed with his coach that Sea Eagles were 'out-enthused' by Newcastle.
"We had to find a way to get back into the game and we didn't really do it too well," he said.
"It seemed like they just wanted it more than us tonight. They just ran a bit harder and tackled a bit harder."
"We have had two good weeks but it just wasn't our night tonight, so we have some work to do."
With the exception of halfback Trent Hodkinson and Lyon, the Manly players seemed almost disinterested at times.
Hasler, however, dismissed the theory that his players had this weekend's clash against arch rivals Melbourne on their minds rather than concentrating on the game at hand against Newcastle.
"Not at all," Hasler said. "We knew coming here tonight it is always a hard venue to play and even harder on a Monday night."
"They played well, let's not take that away from them. But (coming into the match) it was well and truly in our control."
"We had every reason to come here and play well and we didn't. And I am not happy with the 32 points that we let them score."
The loss leaves Manly in sixth place two wins outside of the top four with just five rounds to play. However, Hasler hasn't given up on securing a top two or top four finish.
"We certainly don't worry about that at this stage," he said.
"We have got a important game this coming Saturday and so many of these sides play against each other, so I don't think it is out of reach."
"Today was just a bit of a hiccup that makes it a little bit more difficult for us now."
sportal.com.au