The scenario, which Press Association Sport understands is more likely to happen than not, could even unfold in time for next season.
The potential merger will be a focal point of talks held by Wales’ Professional Game Board on Tuesday.
It is a group that comprises representatives from the Welsh Rugby Union, Scarlets, Ospreys, Dragons and Cardiff Blues.
Establishing a new professional team in north Wales is also high on the agenda in what would be Welsh rugby’s biggest domestic shake-up since regional teams were established 16 years ago.
It is understood that the favoured plan is to retain four regional teams, but they would comprise north Wales, an Ospreys-Scarlets merger, Blues and Dragons.
The Scarlets currently play at Parc-y-Scarlets in Llanelli, while the Ospreys use Swansea City’s Liberty Stadium for their home games.
Any merger would need to establish a home ground, in addition to issues such as the new team’s name and kit.
So-called Project Reset is being played out against a back-drop of Wales chasing this season’s Six Nations title and a possible Grand Slam.
Around half of Wales’ match-day 23 for the Scotland clash is likely to feature Ospreys and Scarlets players.
The WRU has not commented on Tuesday’s planned discussions.
Senior Wales players did meet with the governing body last week, though, to discuss a number of issues on the future of regional rugby.
Speaking last week, Wales assistant coach Rob Howley said: “It’s uncertain times, which is disappointing.
“There is a lot of frustration, not only for the best players in Wales, but for their mates in the regions.
“There is an uncertainty about Project Reset, and they would like to know where they are going to be playing next year or in two years’ time.”
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