Defensive coach Griffiths maintains the playing squad must remain fully focused on the Six Nations Championship clash with Ireland on February 26.
"Personally I feel it is really disappointing for a great friend and colleague," said Griffiths.
"But professionally the job is still to be done and in the short term I am focused on the next challenge, and that is Ireland at Lansdowne Road."
Griffiths added on BBC Radio Five Live's Sportsweek programme: "It has happened and we all have to move on.
"I am not going to pretend it was not a bit of a dark cloud over proceedings [at training], but as time goes on, the wounds are healing and this week we know it is going to be full-on preparation for the Irish game."