Trimble's importance to the Irish game meant Head Coach Joe Schmidt had little hesitation in naming him among a 45 man training group at the start of the summer. Now the challenge for 57-cap winger is to force his way into the final panel of 30, which will travel across the Irish Sea for the eighth edition of the World Cup in September.
Charting his long awaited return to the Ireland camp, Trimble says: "Things have gone unbelievably well - I'm really pleased. I never quite really reached the point where I was rushing my return because I was never going to be fit for the end of the season and that gave me a four week window before pre-season started. I trained very hard to recover, doing a lot of gym work, but now I just need to concentrate on picking up my speed and movement and getting used to all the calls and systems again."
Trimble was a standout performer for Ireland in 2014, scoring a number of tries to help secure a Six Nations Grand Slam triumph. But having watched from the sidelines as the squad retained the title in March, he is well aware that he faces a stiff challenge to force his way back into contention in either the 11 or 14 jersey:
"Joe is spoilt for choice, the standard is so high at the minute," he says. "There are eight wingers in the squad and every single one of them is a quality player; they are serious athletes, their skills are good and they're in in good form. There's a lot of quality in Irish rugby at the minute and things are going the right direction.
"We have four warm up games scheduled in ahead of the tournament, with the squad cut down after the third. It will be difficult for me to make it in - I'll have to perform straight away so it's a big ask, but I'm up for it."
The 30 year old admits that he found it tough watching from the sidelines as Ireland again tasted success and Ulster competed for silverware at the tail end of the season.
"Mentally it was tough," he says. "The two times I missed it the most were when the boys won the Six Nations and when Ulster beat Leinster at Kingspan Stadium - I thought that we were going to kick on and have a great climax to the season. That's the first time I've been injured for that length of time - I think I played something like 55 or 56 Heineken Cup games in a row, so I wasn't used to missing the big occasions for Ulster."
Trimble helped to fill the void with part-time study (a post-grad in Management at the University of London), and fatherhood (his wife Anna gave birth to baby Jack a few months ago). He also took up a new hobby alongside Ulster and Ireland teammate Iain Henderson: "We trained as mechanics for four months and worked on his Mini," he explained. "I have a Mini but it is beyond repair; his at least is on the road but it's probably in worse condition now that when we started," he joked.