Grant McCann admitted Hull City “weren’t good enough” in the disappointing 1-0 defeat by Burton Albion.
Debutant Jonny Smith’s last-minute winner condemned the Tigers to a surprise loss against the division’s bottom side.
“We just weren’t good enough,” admitted McCann.
“We lacked any sort of killer instinct about us today. Things were petering out in the final third.
“We didn’t look like scoring – at all. Movement wasn’t good enough, cleverness wasn’t good enough in and around the box.
“When we did cross the ball, it got blocked or hit the first man. When we shot, it went over the crossbar.
“It’s unlike us because we’ve been really good in that aspect this season.
“Today, we’ve come unstuck with not taking any sort of chance that came our way and getting punished off a mistake. That’s why we’ve lost the game.”
McCann continued: “It’s just not good enough. It’s not what we’ve come to expect from this group of players this year.
“What I said to them (afterwards) was, ‘if we’re not going to win the game, don’t lose it.’
“We switch off. It’s a loose ball from Reece (Burke). One ball in behind our back four, behind Callum Elder and it’s a goal.
“It’s one of those days for us that we have to learn from over the next 24-48 hours and we have to respond Tuesday-Saturday, first off Tuesday.”
Captain Richie Smallwood was withdrawn in the first half through injury following a collision with teammate George Long.
Asked about the severity of the injury, McCann said: “I don’t know until he gets a scan. The scan will be on Monday.
“It doesn’t look too good. Fingers crossed it’s a not bad one. It’s a concern as we’ve got Alfie (Jones) out as well who can play in that position.”