The flanker says he and his team-mates did not deserve to win the game at Sixways, which ended with a dramatic drop goal from Tom Heathcote, who secured a 13-12 win for the Warriors.
It was a disappointing start to the season for Saints, who never really got going.
And Gibson, a summer recruit from Leicester Tigers, gave an honest assessment.
“We probably didn’t deserve to win it in the end,” he said.
“If we’d held out we’d have been jumping for joy because Worcester came out, worked hard and did what they needed to do and they deserved to win the game.
“We let ourselves down in not holding on to the ball.
“We worked hard, you couldn’t fault the boys’ effort, but it’s just that little bit discipline wise, not looking after the ball and Worcester capitalised.”
And when asked about the opposition’s impressive display, he added: “Away from home, on a Friday night... Worcester got out of the Championship for a reason.
“They did well up front, looked dangerous out wide and a lot of teams will struggle against Worcester.
“They are going to keep things tight and they will beat you if you’re not good enough.”