And Percival believes it was a much-needed experience that will stand in them in good stead for the upcoming LV= Cup and Aviva Premiership fixtures.
He said: "We've had to train on astro-turf recently and it affects the forwards as we don't have the opportunity to do some things which we would like to when playing on grass.
"Despite that, the pack did well against Oyonnax last weekend and hopefully we can take that forward.
"We've been able to train on good surfaces in good conditions in Portugal and we have pushed ourselves hard like a mini pre-season. There was a lot of attention to fitness and our condition."
After last weekend's win over Oyonnax, the giant lock revealed that the side's ability to close a game out should give them even more confidence going forward.
He added: "It was a great win. We had a point to prove. The forwards had a good game with driving lineouts and the scrum and we managed the game well in tough conditions.
"The mood is really positive now. We saw that game out and managed the pressure so now that can help us have a winning attitude and increase our belief."
Warriors will be up against Sale for the fourth time this season on Saturday, as the teams do battle in Round 3 of the LV= Cup.
And Percival admits if Warriors were to earn back-to-back victories, it would help the side immensely going forward into the remainder of the season.
He concluded: "We had been looking for that win as wins bring teams together. It's up to us to back up last week's performance by doing the same against Sale this Saturday.
"If we can beat them it would really breathe some more confidence into the side.
"They've had the better of us so far this season but it will be a good test of our attitude this weekend."