Scrum-half Yarnell came off the bench to make his senior bow in the Cup game away to Bath Rugby at The Rec in November, aged 17.
“It’s something my friends keep on to me about,” he said. “They call me ‘Millennium’. It’s good fun. It’s nice they embrace it.”
Yarnell played his early rugby in Nottingham and with Loughborough Grammar School before joining the Tigers academy.
He made his second appearance for the first team when he came on as a second-half replacement in Sunday’s Cup clash at Wasps.
And afterwards he said: “It was a great experience. To run out for the team that you watched since you were five is a dream come true for me.
“Geordan said to go out and enjoy it, and go and put a performance in you can be proud of. I left all I could on the pitch.
“It goes past so quickly so I’ll take a moment to enjoy it.”
Yarnell’s contribution to the cause in Coventry included a deft chip to set up Jonah Holmes for his try.
The scrum-half spotted the Wasps defence had rushed up and lifted the ball behind for Holmes to gather and score his sixth try of the season.
“It wasn’t really planned,” he said. “The chip came out of nowhere really.
“The maul had gone, we had the penalty advantage and I thought why not? I just put boot to ball and it came off.”