Tony Mowbray felt Rovers didn't deserve to lose to Brighton, but one lapse proved costly as they slipped to a 1-0 loss.
Glenn Murray's second half strike was enough to separate the two sides and inflict a first defeat in eight.
Mowbray believed the players more than matched their promotion-chasing opponents, but they just lacked that bit of magic in front of goal on this occasion.
"It looked like a 0-0 all over to be honest," the manager told Rovers PlayerHD.
"Our hope was to nick it 1-0 by scoring from a set-play or one chance to make them anxious.
"It looked to me like it was difficult for both sides to score. Their defence is pretty solid and they have good players in their team, and yet one lapse of concentration makes it frustrating.
"You have to stick with your men in the box, you have to track someone like Murray who is always on the move in the box and it cost us.
"We were good behind the ball today apart from the goal we lost. We showed a fantastic work ethic from the whole team yet ultimately we didn't quite have that magic.
"We competed very well against a team second in the league, there wasn't a big gulf in class, it was a tight match that we could have easily have won 1-0."
Rovers are back in action this Tuesday night when they take on Reading at the Madejski Stadium
Tickets are currently on open sale priced from £20 for Adults, £13 for 65s & over, £10 for 18-24 and £5 for fans aged 17 and under.
Book online today at www.eticketing.co.uk/onerovers/