It was a timely display as a quiet start to the season saw the Scotland forward dropped after the Warriors crashed to a last-minute defeat to the Ospreys in the first home game of the new season.
The application of boot to posterior must have done the trick as John explains in this week's Glaswegian: "Its simple why I played well against Scarlets - I was dropped the previous week and that hurt.
"I can see why Sean did it as I had not started the season well but if it was designed to give me a kick up the a**e it certainly worked.
"I'm a hungry player and when something I want is taken away, when I get it back it makes me more determined to keep it."
You can read the Glaswegian article here