Wales caretaker coach Rob Howley was adamant that the decision to bring Williams back into the Welsh training squad for the Barbarians game was purely on rugby reasons and not sentimental ones.
"It is a common sense approach with the Barbarians game and tour of Australia in mind," explained Howley.
"With two games in two hemispheres in seven days, rest, recuperation and recovery going to be at an absolute premium to our Test players.
"We will be sending key players on the Thursday prior to the Barbarians game but there is no doubt that over the last 12 months the integrated approach Warren Gatland has been part has given us strength of depth in rugby - particularly in the back row."
Williams will have to be content with a starting spot on the bench as Howley said the coaching setup want one of the up and coming players to experience the 'match day experience' but the Blues flanker will still figure prominently in the pre-match routine.
"The easy thing for you to do is talk about sentiment but I assure you it was based on reasonable common sense because Sam [Warburton] hasn't played a lot of rugby since the France game and it is important that we give Sam every opportunity in his rehab to actually play.
"He has an able deputy in Justin Tipuric and along with Josh Turnbull and Aaron Shingler - we feel we have strength in depth in that area. Martyn has been great player and a great ambassador but the decision is based on rugby reasoning and by no means a sentimental one for him to reach 100 caps. I'm looking forward to Marytn's involvement in the game.