Wales captain Alun Wyn Jones was punched by team-mate Jake Ball during training this week, it has been claimed.
MailOnline report Jones will sport a black eye when Wales take the field against Ireland today after the altercation.
Pictures have since emerged of the damage to Jones' face.
The WRU have downplayed the incident behind the scenes after a less than ideal week following the Josh Adams controversy.
Adams was suspended from the squad on Wednesday for breaking national lockdown rules and team protocols by attending a gender reveal party at a relative's home.
Jones will captain the side against Ireland in the Six Nations opener, while Ball is not involved in the squad at all. It will be Ball's final campaign with Wales before he moves to Australia to be with his family.
Speaking about the Adams incident this week, Jones said: "We all realised coming into camp in the Nations Cup there were going to be a lot of firsts. This is just another first and in fairness to Josh he held his hands up and was accountable. Now we move on.
"We had 700 Tests in the Nations Cup which were all negative and we’ve continued in the same vein.
"When Josh comes back I’ll support him and I’ll expect him to let his rugby do the talking."
