Across the 31-year-old’s lengthy career, he has known more productive times in the Champions League than enjoyed in this campaign his club are about to conclude. Doing so in a fashion that seems incongruous. The club have waited more than four decades to earn themselves another evening against Real Madrid in the storied arena of the Bernabeu. Only for it to roll around when the good-but-not-good-enough story of their Group F participation has already been written. Yet, the fact that Forrest has played his part – albeit off the bench – across the five sectional encounters represents another landmark in a game for the hugely likeable character.

This is the fifth Champions League sortie that he has been involved in since he established himself in the senior Celtic set-up 12 years ago. No Scottish-based player has jousted so often in the competition’s group stages with the game’s glitterati. Dead rubbers of the kind awaiting Celtic aren’t unknown to Forrest. Little is at the autumnal stage of a dazzling one-club journey that demands special status be accorded to the attacker. If we must reach for the standard term then, yes, legend it is. Low-key legend might more adequately describe it. It could only be so when the unassuming Ayshire product recently became only the ninth player in Scottish football’s Premier age – a period covering almost half a century – to net in 14 consecutive league campaigns, a feat he accomplished with a hat-trick in a 6-1 mauling of Hibs. A haul that led to him becoming only the 30th player in Celtic’s 134-year history to break the 100 goal-mark for the club.

Only one of his, now 101 strikes, was netted in the Champions League proper (he had a pretty happy knack of netting crucial goals in qualifiers). However, Forrest doesn’t pretend to have known an adventure quite like the one Ange Postecoglou set his team on with complete conviction. Forrest has played in a last 16 tie in the pre-eminent competition in club football – which he did when Celtic came up short against Juventus in 2012-13. Meanwhile, he scored his one Champions League goal, from the penalty spot, when Celtic snared a win against Ajax across a Champions League campaign that brought them five defeats. Never before, though, has he known Celtic daring to look to impose their front-foot game on all-comers, as they have in the past two months. In terms of results, it has left them coming up short – two draws against Shakhtar Donetsk the spoils as they have lost home and away to RB Leipzig, and in their own environs against Madrid. Yet, Forrest can respect, and applaud, the ambition.

Forrest has spent most of his time on the bench this season.

“I’ve said it to a few of the boys that [in the past] we maybe won games where you got one cross, one shot and then you are defending for 90 minutes,” said Forrest. “Sometimes you can get a result that way. But I have felt the boys were well in every game [this season] had our chances, and sometimes we just didn’t manage to take them. But I think it’s definitely promising the amount of chances we’ve created in the five games in the Champions League. The disappointing factor is that the club wanted to be in Europe after Christmas, I think it’s important for the players, the fans, the staff and everyone else as well. Apart from the results, that’s maybe the biggest disappointment, but we still have the other competitions to go for and we need to focus on that.”

Forrest would hate to think Madrid will represent his final excursion for Celtic in the Champions League. Many sought to present him as a spare part earlier this season. Celtic had a phalanx of wingers, and why would Postecoglou turn to him before Jota, Liel Abada, Daizen Maeda and Sead Haksabanovic. The craft and intelligence that Forrest has displayed in recent outings has demonstrated why his manager’s constant bigging up of him by his manager has not been empty words. As the player himself alights on in looking towards his future.

“I signed the deal at the end of last season and I hope to be here for as long as I can,” continued Forrest. “Obviously this season we’ve got so many good players, but when you are playing for Celtic you are in loads of competitions, and being in the Champions League as well, there is nothing better. I think the performances have been really good but it’s maybe just been a bit unlucky that we haven’t managed to get the results and that win in the Champions League that the players and the fans deserve. The hunger is still there, you still want to be a part of these nights.

“The Champions League is massive. Every top European player wants to play in it. There are loads of boys that haven’t played in the Champions League before, and they have loved every game we’ve played in, both home and away. They’ve seen the way the fans have been as well, and for anyone, no matter what age you are, you always want that. You want to continue to be a part of that for as long as you can.

Forrest scored a hat-trick against Hibs in a recent league match.

“I said this to some of the boys who have played in the last couple of games, I think if you look at the amount of chances we have created then we’ve been in every game home and away. We’ve had loads of chances, and that all comes from the manager. Everyone is buying into the way he wants to play, real attacking football, and the more we put in performances like that then the results will come. I think it’s exciting, every player wants to play the way the manager wants to play, and I think that will continue as well.”

Celtic's low-key legend arrives in Madrid hoping this is not his Champions League farewell