Despite bouncing back after half-time with a Josh Adams try, Warriors fell to a 35-8 loss courtesy of three second-half scores for the hosts.
And the boss knows his side must sharpen up quickly ahead of a tough month.
He said: “It’s a bitter pill to swallow. It was a disappointing second-half display.
“I was still pretty confident at half-time as we’d done well and put some good passages of play together but the error rate continued, we played in the wrong areas of the field and our discipline let us down.
“We had quite a few visits to their 22, particularly in the first-half where we had a lot of opportunities but unfortunately we let them slip.
“I still have confidence that we have a good enough group of players but we’re going to have to toughen up.”
Warriors were forced into makeshift changes from the off as Wynand Olivier pulled out in the warm-up with a hamstring injury before Ben Te’o was forced off with an arm problem.
That meant Jamie Shillcock, who started as a travelling reserve, was brought on as a full-back early in the game.
And despite the result, Gold was pleased with the youngster’s impact at short notice.
He explained: “Losing Wynand in the warm-up and Ben in the first-half was disruptive but it’s no excuse.
“Shilly had to come on while Bryce Heem had to move into the centres and at the end of the game we had a loose forward on the wing which wasn’t ideal – but that’s the way the game goes sometimes.
“Shilly saw a lot of the ball and did particularly well especially in the first-half. His kicking game helped us play in the right areas of the field and he’s a great rugby player and considering he had to come in last minute he did very well.”
Warriors host Wasps at Sixways on Sunday 10 September and Gold insists they must regroup quickly ahead of another hard contest.
He added: “It’s not going to get any easier with Wasps, Exeter Chiefs, Gloucester Rugby and Saracens to come but that’s the Premiership – it’s a tough old competition.
“It was a bad day at the office and if we don’t want to be in the same position as last year we’ll have to regroup quickly.”