Frank Lampard admitted his side were beaten by far the better team at Pride Park on Saturday, and that there are many lessons to be learned.
The Rams lost 4-1 to Leeds United to come back down to earth with a bump following the opening day win at Reading eight days earlier, Lampard's men struggling to get a foothold on the game throughout.
And it was a tough pill for the Rams boss to swallow.
He said: "We were under no illusions as to how hard it would be beforehand but we didn't deal with what they threw at us.
"We were well beaten by the better team. They outnumbered us in too many areas and that can't happen. We need to show our quality more and be braver - how we played today went against what we've been working on and what we're trying to produce.
"They moved the ball better and we made too many mistakes that led to goals.
"If you play as we did against a team like Leeds when they're on their game, you'll lose. We didn't have control of midfield in the first-half, hence bringing Bradley Johnson on, and although we were initially better we can't just play good games in small bits.
"The only positive from today is that it's a good reminder for the players that things won't always go our way like they did eventually last week. This hurts, and it will for a few days, but there is a long way to go."
Lampard confirmed that captain Curtis Davies missed the game with a muscle injury that could keep him out for a fortnight, adding: "We'll have to make changes for the Oldham cup game on Tuesday as there are players that need minutes and we're carrying knocks."