A decision on completing the Pro14 season is needed in the next month, Welsh Rugby Union chief executive Martyn Phillips says.
The five-nation league was halted in March because of coronavirus; some teams still have nine group games left.
Holding the knockout stages, or even just the final, look to be the only remotely feasible options.
"I think in the next month that'll come to a head," said Phillips of prospects for the 2019-20 season.
"There comes a point at which... do you just need to write off the season, and try to start the next one as well as you can?
"You keep all your options open until you can't any more, and then there's a point at which the season's gone."
Pro14 organisers have previously ruled that any games in the conference stage which could not be played would be counted as 0-0 draws, while the scheduled 20 June final in Cardiff was written off early in the pandemic.
Unbeaten Leinster, Ulster and Glasgow Warriors are in the play-off places in Conference A, while Edinburgh, Munster and Scarlets are the top three in Conference B.
The international construction of the tournament, with teams from Italy and South Africa joining Welsh, Scottish and Irish sides from the original Celtic League, makes it far more complicated to restart than it would be for domestic leagues.
But unions and broadcasters will be keen to get clubs playing again when public health considerations allow.
"If you do get back to playing, do you play [Welsh] inter-regional games first, inter-provincial games in Ireland? It looks to me as though that is the first port of call," said Phillips before a Pro14 board meeting.
"We have been talking a lot about the international game - but equally in particular the regional game is important, and players do need to play at some point and coaches need to see them back in their environments.
"They are finely tuned athletes and need to play but the safety side is always going to trump [other factors]."
While Wales or Ireland could feasibly stage mini-tournaments, Scotland and Italy have only two professional sides each.
The South African Rugby Union has pencilled in a possible tournament pitting its two Pro14 sides against the country's four Super Rugby outfits if domestic sport can resume. Further afield, New Zealand franchises are in line to face each other in June behind closed doors.
Phillips says talks are ongoing about a return for Welsh rugby at all levels as the WRU await government guidance.
"There is also the club game and Premiership teams that I'm sure are itching to get back on the pitch and we're in that conversation about when do they start back," said Phillips.
"There's also the community game and all facets of that, and we have a discussion session next week on the women's game and the sevens.
"We're on calls every day talking about how we (can be) as ready as possible to start up again when we get the green light."