Jonny Lomax’s season is over after he suffered a serious injury in last weekend’s game at Catalan.
The 23-year-old damaged his knee in the second half and needs an operation.
Saints Head Coach Nathan Brown said: “This is obviously a blow to the team but more importantly to Jonny. He has been in great form and has settled well into the full back position.
“He will now begin his road to recovery led by our medical staff and we wish him well. Jonny has a strong character and we’re sure he will come back and prove once again to be a pivotal player for us.”