Gone are the centre-cum-winger's golden locks, but his steely determination remains. Trimble will be fighting his way back to full fitness over the summer months as he recovers from the recent leg operation which kept him out of Ireland's summer tour to New Zealand and Australia.
The 23-year-old reckons that the new season could the start of something good for Ulster Rugby, with the squad already setting the aim of reaching the Heineken Cup quarter-finals.
The province's players and supporters are desperate for a return to the glory days of 1999 and that famous Heineken Cup triumph at Lansdowne Road.
Only full-back Bryn Cunningham and prop Justin Fitzpatrick remain from the Ulster team that beat Colomiers in the European final and Trimble, who was studying in Coleraine Academical Institution back then, is eager to be part of the first Ulster team to qualify for the competition's last-eight since 1999.
Tuesday's draw for the 2008/09 Heineken Cup threw Ulster in Pool 4 alongside Stade Francais, Llanelli Scarlets and Harlequins. English side Harlequins are new opponents for them but they have previous history with both Stade and Llanelli.
Giving his thoughts on the draw to BBC Sport, Trimble said: "I don't think it was really going to take much to excite us for next season after really a disappointing season last year. We're raring to get going again.
"Some of the guys are starting (pre-season) now. It's going to be a long pre-season, very rigorous and an awful lot of work to be done. And hopefully we'll reap the benefits next season with a few results.
"Whenever you look at some of the sides that are out there and the quality there is in Europe and England and France in particular, you could do a lot worse (in the draw).
"Having said that, this is the Heineken Cup and I don't think there's such a thing as an easy draw or an easy match," he added.
"We really have to regain our home form and we have to get a couple of results on the road as well. It's very demanding, especially with Stade Francais in there. All these teams can produce big results.
"I think we're going to be up against it but no more than we have been."
Ulster had a disastrous Heineken Cup run last season, with their then coach Mark McCall resigning in November, just a few days after their 32-14 pool defeat at home to Gloucester.
Assistant coach Steve Williams took up the reins with January's 25-24 home win over Bourgoin, in which Trimble scored the match-winning try, being their only real highlight in Pool 2.
Having secured Heineken Cup qualification via their position in the final Magners League table, Matt Williams' charges, with some notable summer acquisitions on board, now look in far better shape to challenge for domestic and European honours.
But getting the better of Stade, Llanelli and Harlequins will be no easy task, Trimble agreed.
"What I remember of the Stade match in 1999? I was very small at the time. The one thing that sticks out in everybody's mind is (David) Humphreys' try. I don't think anybody's ever going to forget that. It would be great if something like that could happen again.
"I think all these sides in our pool are beatable but they're also capable of producing big performances.
"You know, Llanelli last year were in a very tough group. I think they played extremely well in a couple of games but didn't get the results. I don't think we can afford to overlook them.
"Harlequins, we know very little about. That will be a difficult game as well. We're certainly not taking anything for granted.
"We'll have to work extremely hard and with a lot of changes in personnel and systems in Ulster Rugby, we're really hoping we can turn a corner in September and be a tough side to beat."
On a personal level, Trimble is just looking forward to getting himself physically right for the new season. The leg operation was a much-needed one, coming at the end of a year packed full of Magners League, Heineken Cup, Six Nations and World Cup games.
The powerfully-built back, who will be hoping to be in Declan Kidney's squad for Ireland's autumn internationals, revealed that 'the op was very successful.'
"The doctor was very pleased with how it went, everything went according to plan. I've had a week not doing anything, trying to recover.
"I've just been starting to do some rehab and getting back into some exercises. Hopefully I'll be running in a few weeks yet.
"I'd like to think I'll be ready for the new season. Hopefully I'll get back and still have a few weeks' leg weights and running and get back fast and fit again."