Huh blamed several factors after title holders South Korea lost to China in Tokyo on Wednesday for the first time since the countries began playing full internationals in 1978.
"That unbeaten record had to end one day," Huh told reporters. "But we had a few players come into the side who weren't in tune with the way we play.
"China never let us settle and once we gave away those two goals in the first half we were always chasing the game. I give credit to China but our conditioning wasn't good.
"They hit us on the break and took us out of our comfort zone. We didn't deal with their energy well at all. They forced us to rush our play."
Although missing Europe-based players such as captain Park Ji-sung of Manchester United and Bolton Wanderers Lee Chung-yong, a first defeat by China in 26 meetings was a blow for the Koreans.
Huh's side need to beat hosts Japan on Sunday to have any realistic hopes of retaining their East Asian title in a game with added significance with the World Cup four months away.
The Asian rivals have both qualified for South Africa but neither have impressed in their warm-up games, South Korea's 5-0 rout of Hong Kong in their East Asian opener apart.
"I'm not afraid," said a defiant Huh. "We have to accept the result against China, analyse our mistakes and fix them in time for the Japan game."
Japan were playing Hong Kong later on Thursday looking for a big victory to boost their chances of a first East Asian title.
