Co-caretaker manager Liam Rosenior said bottom-of-the-table Derby County's performance in the 3-0 defeat against Middlesbrough was "unacceptable".
Rosenior, part of a four-strong interim coaching team also including Wayne Rooney, Shay Given and Justin Walker, saw the Rams lose for the second time since they took charge.
The defeat was also Derby's fourth in a row, all of which have seen them fail to score.
"I am not going to stand here and make excuses," Rosenior said. "I just am speechless in what I saw first half in terms of desire, passion, and winning duels.
"I can accept losing when you put a performance in and you put intensity in and energy in the game. I can't stand here and defend that. I can't defend myself, I can't defend anything about this evening.
"That was unacceptable. Attitude is absolutely everything. I want to see a team that goes out on Saturday and gives everything for this football club and what the fans deserve. I can only apologise to them and everybody surrounding the club for that performance."
Boro striker Britt Assombalonga poked the ball in from close range to ruin a bright start by the visitors.
And although Rooney, England's record goalscorer, moved further forward after the interval to try to provide a cutting edge and reward their territorial dominance, they continued to misfire in front of goal.
Substitute Louie Sibley twice went close to grabbing an equaliser, only for a flowing move to end with Matt Clarke, under extreme pressure from Assombalonga, turning the ball into his own net to put Middlesbrough 2-0 ahead.
Boro, under their ever-wily 71-year-old manager Neil Warnock, then piled on further misery for disheartened Derby when Marvin Johnson curled in a delightful third home goal into the far corner.
And the hosts could have added to their tally on the way to a win that takes them up seventh in the Championship table.
Derby fire blanks again
Defeat means Derby have only managed one win in 13 league games so far this season, scoring just five goals.
The scoreline was harsh on Rooney's side, but the experience and tactical nous of his counterpart won through.
Warnock, whose appointment by Boro in June saw him take charge of the 16th club of his managerial career, has now reached 1,509 games as a boss.
Rooney has said he wants to take the job on a full-time basis and former England boss Steve McClaren is set to take on the role of technical director in his third spell with the club once a proposed takeover by Abu Dhabi-based Sheikh Khaled bin Saquer Zayed Al Nayhan, goes through.
McClaren was an interested onlooker as another of his former sides Boro soaked up some solid Derby pressure in the early stages at the Riverside before taking the lead.
"He had no input with the tactics or team selection, but I'm delighted he's here because he's someone who has been there and done it," said Rosenior.
Assambalonga had the first chance of the game, a strike from the edge of the area that was well saved by Scotland keeper David Marshall.
The Rams were on top thereafter, edging possession and looking neat and tidy. But as in their first match under their caretaker coaching quartet against Bristol City following the sacking of Phillip Cocu, they lacked a telling threat up front and struggled to create chances.
Tom Lawrence did well to fashion a strike for himself from 18 yards that was held by Marcus Bettinelli and Max Bird sent another shot from distance narrowly wide.
Sibley almost scored within 30 seconds of the restart, only to shoot just past the post and he went even closer with a decent low strike that forced Bettinelli into a scrambling save.
However, Boro, who have conceded a division-low six goals from their 13 games, made it 2-0 when Djed Spence played in Johnson on the left flank and his low cross was diverted in by Clarke.
There was still time for a third goal against an increasingly stretched defence, as Johnson showed poise and class to bend a beautiful strike into the far corner.
Middlesbrough boss Neil Warnock on bringing in Duncan Watmore and Patrick Roberts:
"It's a hard league this league, and you've got to get goals. You've got to look at how you can get more goals, and I felt the only way we could get more goals was by being a bit more positive in the wide positions.
"Even when we changed it and had two full-backs again (after the substitutions), they were still more positive.
"It's not a natural thing for a wing-back to makes runs inside and support a striker, whereas Duncan does it automatically.
"Marcus Browne, who is injured at the minute, is the same. You've got to have something like that in games. It allows us to have different options instead of just being rigid."