The Neath-Swansea Ospreys have opted not to play any matches at the former home of the defunct Celtic Warriors.
The Morfa Stadium will provide a new home for the Ospreys
It had been hoped that the Brewery Field in Bridgend would still be a home for top-flight rugby.
But Ospreys management and former Warriors chief Leighton Samuel have conceded that the cost would limit the number of games to a "token gesture".
St Helen's and the Gnoll will have less games once the Ospreys have use of the new Morfa Stadium next season.
Ospreys chief executive Andrew Donald said: "We've had a number of key discussions with Leighton about holding fixtures at the Brewery Field.
"It's become abundantly clear that, while seeming like a great idea on the surface, the reality of actually staging a game at Bridgend is fraught with difficulties.
"Aside from logistical problems like the number of seats versus season-ticket holders, we are both acutely aware that the move could actually alienate three sets of supporters."
The Ospreys have been trying to forge links in the former Warriors areas they have taken responsibility for.
Originally an amalgamation of Pontypridd and Bridgend, the former Warriors set-up suffered from in-fighting between its two parts.
But Bridgend chief Leighton Samuel, who owns the lease at the Brewery Field, believes the move to Morfa - which the Ospreys will share with Swansea City football club - will herald a fresh start.
"In reality the Ospreys were only ever likely to play one pre-season home game here," Samuel said.
"Whilst I know the gesture will be hugely appreciated by both Warriors and existing Bridgend fans, I think we all agree that a longer-term view should now be taken.
"In particular this means focusing on the opening of the Morfa Stadium and using this new neutral facility, without historical ties to any one club, as a way of integrating fans from Bridgend and the surrounding area.
"This will allow for a real and lasting support base to be created, rather than relying on a one-off token game at the Brewery Field as a way of appeasing fans."
The Ospreys depart on 10 August for a six-day training camp in France at Bagneres, in the shadow of the Pyrenees.
The training camp includes a fixture against last season's Heineken Cup finalists Toulouse at Bagneres on 12 August, kick-off 1900 BST, 1800 CET local time.