Although the grab was more of playful pinch than any attempt to seriously hurt Mason, the Newcastle chief executive Matt Gidley has stated that the action was still inappropriate.
Images and videos of the incident have been shared widely over social media in the last few days, attracting widespread media attention across the world.
Gidley has affirmed that he has no intention of fining or suspending Sims.
“From our point of view, while it was light-hearted in nature, it was clearly inappropriate and it won’t happen again so we’re all looking to move on from it,” Gidley told reporters Down Under.
“There’s probably going to be an opportunity for me to discuss it with him tomorrow but that’s as simple as the conversation will be.
“I saw Willie’s comments today, and the fact that they’re friends and were teammates for the past three years, there’s no doubt it was light-hearted.
“But again, there’s no doubting it was inappropriate as well.”
Mason himself was hopeful that the player would not be charged for something so light-hearted in nature.
“We are really good mates and I think it was unlucky because of the timing of it all,” he said.
“I knew what he was doing. I was talking to him as he was doing it.
“I didn’t even flinch. It was quite funny to me. He’s just a good young kid and I would hope that nothing is done because of it.”