That may have seemed an unlikely scenario given that the 29-year-old made only one appearance for Ireland in 2013 - playing in the summer tour win over Canada - and failed to feature during last November's GUINNESS Series.
But having been given his opportunity by head coach Joe Schmidt, Trimble has really grasped it with both hands and shown arguably his best ever form in the green jersey - with former Ireland captain Keith Wood dubbing him 'a revelation' this season.
He scored his third try of the Championship in the 22-20 title-clinching victory over France, and it was his break that set the attack in motion for Jonathan Sexton's second try of the night.
He has used his athleticism to very good effect in both defence and attack - most notably under the high ball - as well as nailing some crucial tackles throughout the campaign and being a key component of Ireland's kick chase.
Speaking to BBC Northern Ireland after the French game, Trimble admitted: "It's very difficult to be put into the words. I've never been so tired in my life, the boys just slogged it out out there.
"We just put in eight weeks of really, really hard work on the pitch and off it, the preparation...it just shows if you put the hard work in, we've got the talent, we've got the players, we've got the coach and we can get results.
"For me, this is definitely the highest point of my career. All the hard work paid off, it just means so much."
Apart from the tries against Scotland, Italy and France, it was Trimble's work-rate on and off the ball and his physicality which saw him earn plaudits throughout the tournament.
"I suppose it's definitely up there. It's definitely the most memorable for me," said the Ulsterman when asked if the Paris performance was his best yet in an Irish shirt.
"I've spoken about this before, I was fed up letting opportunities pass me by, individually, and we were fed up as a team letting opportunities slip through our finger tips.
"And then today we just made it count. You know, put the work in and it pays off and everybody in there (in the dressing room) is just over the moon."
Whenever Trimble is interviewed he always gives a very honest assessment of his own game, a trait he shares with friend and former Ireland team-mate Ronan O'Gara who, when he chatted to Trimble at pitchside before the Championship opener against Scotland, urged him to 'just go out and do what you do for Ulster'.
Transferring his form with Ulster onto the international stage has proven difficult to do over the years, but O'Gara was delighted to see the Belfast-born back deliver in the Paris cauldron.
Speaking with Trimble in a post-match interview for RTÉ Sport, O'Gara said: "Trims, for me I think there's a message here in persisting. You were outside of the group in the November internationals, you stuck at it, you've 50 games for Ireland.
"I think there's young kids going to bed dreaming of being the next Andrew Trimble after your performance today. It means that much. It was unbelievable for us to watch here today.
"Paris suffocates players, but you grew six foot out there. I see it in training and it's great for the people of Ireland, the public back home and all those celebrating tonight, to see the Andrew Trimble that we've all seen in training."
Giving his own assessment, Trimble insisted: "I've put on a green jersey many times now, and more often than not I've underperformed in it. I've just been disappointed with it.
"I sat down with the likes of Joe and Mervyn Murphy, our video analyst, and went through some things.
"I've worked on little bits and pieces and finally it has all come together and just to put it together with the Championship means the world to me."
The man he says he has 'learned an awful lot from over the last eight weeks', Ireland head coach Schmidt, described Trimble's contribution in the title decider as 'immense'.
"There's probably some forgotten guys who, I think, have been fantastic throughout the tournament," said the New Zealander.
"I thought Andrew Trimble was immense (tonight). He made some great decisions, he showed some great skill and his acceleration was good."