Warrington marquee signing Gareth Widdop is set to miss the start of the Super League season with a "lower limb injury" picked up in training.
The England and Great Britain half-back, 30, sustained the injury after rolling his ankle.
Challenge Cup holders Warrington said he could return for their game with Toronto on 21 February.
Widdop joined Wire from Australian National Rugby League club St George Illawarra on a three-year contract.
He was part of Wayne Bennett's Great Britain Lions tour of the southern hemisphere last autumn, after overcoming three shoulder injuries.
Warrington open their Super League season at Wigan on 30 January before hosting St Helens on 6 February and travelling to Wakefield on 16 February.