Cardiff Blues say they are considering moving from their Arms Park home.
The Welsh rugby region says a failure to negotiate a new lease beyond 2022 with landlords Cardiff Athletic Club (CAC) is behind the decision.
Blues’ statement said: “The board are in agreement that they must future proof Cardiff Blues by exploring alternative options away from Cardiff Arms Park.
“There are a number of exciting opportunities available.”
Blues had put forward plans to give the stadium a multi-million pound facelift but that plan was rejected by CAC in early 2017.
In May that year, Blues said a possible temporary takeover of the team by the Welsh Rugby Union, the sport’s governing body in Wales, had been called off.
In October of that year CAC said they were willing to discuss a new lease “to secure the future” of rugby at the ground.
Cardiff RFC, who play in the second-tier Welsh Premiership, also call the city centre Arms Park site home.
Blues moved to Cardiff City football club’s home in the Leckwith area of the Welsh capital in 2009.
Three seasons later, at the end of the 2011-12 season, that move was aborted as Blues returned to their traditional home.
CAC are due to hold their annual general meeting on 7 February.