The prop started on the tight head in both Aviva Premiership victories and says the squad aren't getting carried away with what has been a positive start.
"I think the good thing about the two wins so far is that the whole squad have come back and identified plenty still to work on," Mercey told Wednesday's press conference. "We believe we can still get better and that there is plenty of room left for growth in the style of rugby we are playing and what we can do.
"I think everyone knows we haven't reached our best yet."
And while Gloucester tasted defeat in their opening pair of fixtures - including a Round 1 upset at Kingsholm by Sale - Mercey is all too aware that form can turnaround quickly, particularly at one of the fortresses of the Aviva Premiership.
"I think it's too early in the season to read too much into stats and standings. Only two games have been played and sides are still finding their feet and getting used to playing again.
"Gloucester are a team that are going to be competing to be in the top four so we've got to go up there and acknowledge that; A - We're playing at Kingsholm; and B - We're playing against a dangerous Gloucester side.
"We've got to respect them and play well to go up there and get a win and if we don't do that then Gloucester will get the better of us."
You can watch this Saturday's 3:15pm kick off live on BT Sport, or follow the club's usual minute-by-minute commentary online.