The winger has benefited from injuries to Dave Kearney and Fergus McFadden and has taken his chance with both hands - he has arguably been Matt O'Connor's most consistent performer this season.
Despite being a mainstay in the starting XV, he admitted that the competition for places is so intense that he isn't naive enough to think that he has cemented his place in the side.
"Yeah, every minute of every week at the moment. Long may it continue," Fanning replied when asked if he felt that his place was under threat by the returning players.
"You basically always have to focus on your own game. There are a lot of great players coming back."
It's been a whirlwind journey for Fanning but having spent time at Carton House in Ireland camp this month, he realised just how far he had come in such a short space of time.
"I thought it (professional rugby) was gone for me two years ago. I never thought I'd play a Pro12 game, let alone in European Championship games."
As well as his consistent performances, Fanning has now added tries to his game but he insisted that they were always part of his make-up.
After two injury-hit seasons with Connacht, the 28-year-old only made his Leinster debut in 2013.
In his own words, two years playing semi-pro rugby in Australia appeared to have ended his lifelong dream of playing professionally but as he gazes around the surroundings of Leinster's UCD headquarters, he feels right at home.
"It's funny, one of my coaches from Australia, Dan McKellar, who's actually an assistant coach with the Brumbies now, rang me a few weeks ago and started slagging me," Fanning smiled.
"When I left there, I remember really well I was leaving Australia to come home to start work which I did and he was talking about contacting Calvisano and that he could get me references from Laurie Fisher and Jake White.
"He quoted me on this - that I actually said to him I'd have more chance of winning the Euromillions next week than picking up a contract at home.
"So that's how I thought about it coming home. It just shows that getting a few games in the AIL and getting lucky, it shows there are still opportunities there.
"A lot of lads think that if you pass the Leinster 20s and you're not being selected, then that's it. But hopefully I've proved them wrong.