Rovers boss Gary Bowyer admits his side were undone by two soft goals in the defeat at Derby County.
Substitute Darren Bent netted twice for the hosts and Bowyer was bitterly disappointed after frustrating Derby for much of the game.
"We are very disappointed," said the Rovers manager. "We came with a game plan to frustrate Derby and it was working well.
"We competed for most parts of the game and at half-time we just told the lads to stick at it and keep going.
"Unfortunately, we were undone by two pieces of really poor defending and there is no excuse for that.
"Obviously Darren Bent has got Premier League quality, but his goals were too easy. Scrappy, horrible goals.
"We kept plugging away, but we were disrupted by three injuries and some soft defending, which isn't acceptable."