Rotherham boss Paul Warne felt his side were undone by poor defending against Hull, rather than the wrong tactics.
The Millers slipped to a 3-2 defeat against the previously winless Tigers at the AESSEAL New York Stadium on Tuesday.
They went ahead through Richard Wood but Jackson Irvine's double and Fraizer Campbell's effort put Hull in control before Jamie Proctor made a game of it in the final 15 minutes.
Warne opted to start the match with a lone striker in Michael Smith, packing the midfield instead, and insisted that was the right call.
“It's pretty obvious really, we played two up front against Brentford and got hammered,” he said.
“We played two up against Ipswich and didn't get a kick in the first half until I put Vas (Kyle Vassell) out wide and then we were a much better team.
“I played one up against Leeds and I thought our shape was really good in and out of possession of the ball.
“The way Hull played, they keep the ball quite a lot, and I think if we'd have played two up front our two wouldn't have got a look-in.
“And that means we have to go back-to-front, direct all of the time.
“If it was my mistake and we lost the game then I will hold my hands up, but I think we were set up right and we were hard to break down and unfortunately individual errors have cost us a little bit.”
Things looked rosy for the Millers after Wood's 16th-minute header until Irvine was given the freedom of the box to level up.
Then more slapdash defending either side of half-time allowed Hull to earn a two-goal advantage and that was where the Millers were hurt, says Warne.
“I'm hugely disappointed with the goals we conceded,'' he added.
“The two minutes either side of half-time decided the game really. Both goals were avoidable, I'm not disrespecting Hull, they played well, it wasn't like they were cutting us open every time.
“We need to eradicate that because we can't gift teams goals in this league.”