Cardiff Blues will use a council-owned leisure centre when they return to training ready for August's Pro14 restart.
The Arms Park is unavailable as it is being used as the headquarters for the Dragon's Heart Hospital housed at neighbouring Principality Stadium.
Blues will have exclusive use of a gym, medical facilities and 3G surface at Pentwyn Leisure centre.
They will also continue to use a grass pitch at Sophia Gardens in the city.
The region previously had a training base at the Vale of Glamorgan resort, but returned to the city centre for 2019-20.
At that time Blues said they planned to return to the Vale base for 2020-21.
Their new short-term agreement has been reached with Cardiff Council and GLL who operate the leisure centre in the east of the city.
This follows the agreed government and Welsh Rugby Union (WRU) advice for professional rugby clubs returning to training and implementing recommended player and facility protocols linked to Covid-19.
Blues chief executive Richard Holland said: "We are thrilled to have such a facility in place to support the squad's phased return to playing and I would like to thank Cardiff Council, particularly council leader Huw Thomas, chief executive Paul Orders and cabinet member for culture and leisure councillor Peter Bradbury, as well as GLL for their support in this.
"With the Arms Park continuing to play a role in the Dragon's Heart Hospital we required a top-class facility and all relevant parties have pulled together for a positive solution."
Current Welsh government plans will see a phased reopening of leisure facilities, once the Welsh government has confirmed a reopening date, to ensure that new Covid-safe working practices are implemented.