Tony Mowbray believes the below-par performance against Bury is what cost Rovers from making progress in the Checkatrade Trophy.
Rovers bowed out of the competition on Wednesday night following Bury's 3-1 victory over Stoke City's Under-21s, which saw the Shakers join Rochdale in the knockout round.
Mowbray's men had kicked off their campaign with a 1-0 victory over Stoke at Ewood Park - in which young hot-shot Joe Nuttall scored his first senior goal for the club - before slipping to a 1-0 defeat at home to Bury.
Despite being forced to play over an hour with 10 men in their final group game against Rochdale on Tuesday night, Rovers produced an impressive performance to hold the hosts to a 1-1 draw, before missing out on the bonus point, losing 5-3 on penalties.
Mowbray believes that key decisions went against Rovers throughout the competition, but it was the disappointing display against Bury that bothered him the most.
"In the context, of course, you want to win every game, but I would have to say the Bury game was really disappointing," said the manager.
"I thought the Stoke game was ok, we played some nice stuff against Stoke and Joe came off the bench and scored the winner that night.
"Against Rochdale, there was lots of good stuff, but we didn't qualify out of this group because of the Bury game."