Richard Hill pinpointed a lack of parity at the set piece as crucial as Warriors suffered a late defeat to London Wasps on home soil.
A try from Richard Birkett in the closing minutes ensured the Londoners took the points and left Warriors with just a losing bonus point.
Defeat was harsh on Warriors who defended superbly throughout to deny Wasps the chance to build a platform to release wide boys Tom Varndell and top try scorer in the league Christian Wade.
However, Hill warned his team they need to rediscover their edge in the set piece if they were to turn battling displays into victories.
“The first half we failed to establish set piece parity and the difference between the two sides, and it was accentuated in the first half, was the Wasps scrum was solid and their lineout certainly was,” he said.
“We just couldn’t get near their lineout and they produced good quality ball for the nine to kick or drive and give to Nicky Robinson to play in the backs.
“Contrast that to us and we lost the first three lineouts and had one in the second half when Jake Abbott dropped the ball. You think you have won nice clean ball, the only one all night really, and we drop it.
“On a night like tonight you have to have parity in set piece and a platform to work from.
“Joe Simpson tonight was sat behind the Wasps pack and was able to kick well because he was under no pressure. Shaun Perry was constantly digging ball out and having to battle for bits and pieces.
“We just didn’t get enough ball to the backs, despite the fact that Joe Carlisle played very well and looked lively when he had the ball.
“We decided to make changes at half-time,” added Hill. “Our lineout didn’t function and when Aleki Lutui came on it was a bit better. He also offered quite a bit around the field and carrying.
“Some of our kicking was poor and we couldn’t get out of our third. Joe kicked well for position and ran the game well in the second half so that, along with our defence, were two plus points.”