Any hopes Mike Phillips had of making his Bayonne debut at Biarritz on Saturday have been dashed by an outbreak of mumps in French rugby.
Bayonne's trip to their neighbours has been postponed because players from Biarritz's recent opponents Lyon have been diagnosed with the illness.
Lyon's games with Bordeaux-Begles and Montpellier have also been postponed.
Phillips' former team the Ospreys are due to face Biarritz in the Heineken Cup on Saturday 12 November.
However, two of Phillips' former Ospreys team-mates, Lee Byrne and James Hook, are poised for their Top 14 debuts at the weekend.
Full-back Byrne's starts for new club Clermont Auvergne at Stade Francais on Saturday, while Perpignan could field versatile back Hook at Toulouse earlier that day as the players return to club rugby after their post-World Cup efforts.
Biarritz drew 15-15 with Lyon on 22 October and some Lyon players were later diagnosed with the contagious illness.
And although Biarritz played a week later in a 41-0 defeat by Clermont Auvergne, their next scheduled game has now been postponed.
Lyon's clash against Bordeaux-Begles on 29 October was called off.
And the French league's authorities have also ruled Lyon cannot take on Montpellier on Saturday 5 November, when Bayonne were also due to play Biarritz.
Phillips' next opportunity to play for his new club comes on Saturday, 12 November when they travel to Rovigo in the Amlin Challenge Cup.