Paul Trollope said today's 5-4 defeat against Peterborough United was a "huge disappointment".
The first team coach watched his side produce a poor defensive display to go down in a nine-goal thriller at London Road.
"It was a good attacking display, to score four goals away from home is pleasing, but we were very poor defensively," Paul told bristolrovers.co.uk.
"We didn't cope with their forward play, and with their front two in particular. I think both teams should be disappointed with their defending, and from our point of view there are some areas we need to address quickly.
"Usually we're pretty well organised with that aspect of our game, but today they were too much for us. We didn't defend one-on-one situations collectively or individually, and there were clear issues for all five of their goals.
"We need to address things, we need to arrest what's going on and to stop it. No matter how well we pass the ball and attack going forward, we're not going to win games if we defend like that.
"Even at the end of the game, despite chasing at 5-4, I still felt we had a chance. We should have scored more, and just before half-time when we had grown into the game we missed some one-on-one chances that we should have taken.
"And then to go behind just after the break meant we were always going to be chasing and up against it.
"It was a big effort from us, but the outcome is a huge disappointment. We had high hopes of an away win, but it's clear today that there are some areas of our team that need serious working on."
