Alun Wyn Jones has undergone a scan on the knee he injured played for Wales in their Autumn Nations Cup finale against Italy.
Test rugby's all-time appearance record holder is also believed to have had a consultation with a specialist.
His region the Ospreys and the Welsh Rugby Union are still awaiting confirmation on the results of the scan.
Both will be hoping for good news.
The 2021 Six Nations begins in just over eight weeks with Wales facing a tough opening against Ireland before heading up to Murrayfield to take on Scotland and then returning home for a joust with England. All three of those sides defeated Wales this autumn.
For the Ospreys, there are four European matches sandwiching three Welsh Guinness PRO14 derbies.
The initial suggestion, as conveyed by Pivac after the 38-18 win over the Azzurri, was that Jones had suffered medial ligament damage.
Recovery time from a medial ligament problem varies according to the severity of the injury.
A grade 1 tear (a strain or an overstretch) will usually heal within a few days to a week and a half.
A grade II tear (partial or incomplete) may take between two and four weeks to heal.
And a grade III tear (full) can take four to eight weeks to overcome.
Jones began showing signs that all was not as it should be shortly before Gareth Davies raced clear for Wales’ third try against Italy, with the team's talisman having difficulty rising to his feet after being left strewn across the floor.
The hobbling skipper managed to head towards the defensive line, only to collapse in a heap as Davies sped through the Italian cover.
Treatment from medics saw Jones resume for five minutes before leaving the field in obvious pain.
The 35-year-old lock, who won his 152nd cap last weekend, remains central to Pivac’s plans as the New Zealander tries to plot a route forward after a difficult autumn campaign for Wales.
Jones will also want to make the Six Nations starting grid in a Lions year that's likely to see places dished out largely according to efforts in the tournament.
