Fainga'anuku was initially signed in September 2012 as cover for the front row as the Warriors went through a mini-injury crisis, but the Tongan has impressed the coaching staff and last week it was revealed he will be staying on until the end of the season.
Capped for Tonga and a former member of the playing staff at The Waratahs in Super Rugby, the loose-head is delighted he'll be calling Glasgow home for at least the next few months.
He said: "I'm very happy to be staying and very happy that I'll get a chance to keep proving what I can do.
"I had a shoulder injury just before Christmas and that makes you think about whether you're going to be kept on or not.
"The other thing is, with staying on, you get to know the area a little better and my wife likes it here so it's nice to know that the family has a little stability.
"We don't have to pack up and we can stay and play our part in the rest of the season for Warriors."
Six feet tall and 19st, the 30-year-old has endeared himself to the Scotstoun crowd with some powerhouse displays and a fearsome, some say typically South Sea, attitude to tackling.
He's made six appearances for the Warriors and each time to acclaim for his ability in the loose.
Ofa puts that down to his background in the game's other code.
He said: "I like the way Glasgow play and I have learned a lot from the players here and what Gregor (Townsend, head coach) wants to do with the team and they are a good bunch of boys who want to play good rugby.
"I think it's from my rugby league background that I enjoy getting stuck in around the contact area. If someone's running my way, I'll just drop my shoulder and try and put in a big hit."
It may be a blunt and forceful approach but it's one that is working for Fainga'anuku and the Warriors.
He starts on the bench for the match against Newport Gwent Dragons tonight in Wales.
It's a crunch game for the Warriors who are coming off the back of a five-try win away to Italians Zebre and currently sit in second place in the RaboDirect PRO12.
The Scotstoun side face the league leaders, Ulster, at Scotstoun Stadium a week tonight as they push for a home tie in the league play-offs.