A year ago, their stunning UEFA Cup exit at the hands of Trelleborgs registered pretty high on the Richter scale.
Last night was, in some ways, Trelleborg revisited, though soccer's seismologists will tell you that this defeat was not quite as unexpected as the one in Sweden.
Simply an after shock, following the main quake.
But Rovers, lifted by their wins over Swindon and Coventry, certainly came down to earth with a Norwegian thud of quite significant proportions.
It was hell in the Lerkendal for much of the game for a depleted team struggling to play their way in the Premiership, let alone match the high rollers of the UEFA Champions' League.
Rosenborg aren't exactly in the executive class.
But, make no mistake, they are a good team. Very experienced in Europe and - no offence - with bigger scalps than Rovers hanging from their belt.
Having said that, we expected so much more than what the Ewood side actually produced. They almost got out of jail but no-one could argue about the justice of the result, only be thankful that the margin of defeat wasn't greater.
All it needed was to hear the tones of that notorious commentator, mocking English efforts once again, to complete the nightmare in Norway.
Rocking from the speed and subtlety of Rosenborg's superb counter attacking power, Rovers seemed to have survived the worst.
And, having clawed their way back into the game to draw level, a first Champions' League point beckoned with just four minutes remaining.
But then came another shudder in their defensive ranks, allowing Stale Stensaas to crash a mighty winner and - let's be fair - give the game the result it deserved. Memories of that haunted, horrible night in Trelleborg, just a year ago, came flooding back as a late goal condemned Rovers to be losers again. And, with their present resources unable to be supplemented for the Champions' League - apart from men returning from injury - you wonder if it's already too late on the European front.
The pace and positive attitude shown by Rosenborg proved far too much for a Rovers side who were leaden-footed in the Lerkendal, apart from one period, when Mike Newell scored a long-awaited goal and Rovers threatened to take charge of the game.
But it was a false hope.
Everything wasn't coming up roses - except for Rosenborg.
There will be much criticism of what is wrong with Rovers in particular and English football in general.
As far as Rovers are concerned, one major aspect is the width - or the lack of it.
Wide boys Stuart Ripley and Jason Wilcox were one of the crucial factors in Rovers' success over the past three years.
And the loss of form of Ripley and the absence of Wilcox through long-term injury has been a key to the recent decline.
Perhaps it is only now that many are realising just how vital they were to the cause. Not just in an attacking sense but also defensively.
The loss of Graeme Le Saux made it worse, leaving the side without a genuine left-sided player. Little wonder they looked unbalanced.
And, not for the first time this season, I have to say the edge, the spark, seems to have gone.
You could see it as plain as the fact that Rosenborg deserved to win.
In the first half, Stensaas continually pushed forward down the Norwegians' left to cause big problems.
His excursions also freed one of the main Rosenborg danger men, "Mini" Jakobsen to roam at will and Rovers simply couldn't afford to continue to let that happen.
They brought on Stuart Ripley at the start of the second half and, as well as acting as a deterrent, it also - finally - gave some much-needed width to their own attacking play. And if you give the strikers Rovers possess some half-decent service, they will get goals. Before half-time the build up and movement was too ponderous.
With their wings clipped and no-one from midfield looking capable of cracking open what I suspect was a modest home defence chances of a first half goal were remote.
Only Alan Shearer promised something but he had to spend too much time trying to set things up.
When you have a striker like Shearer, or Chris Sutton, you have to give them good service in the areas they can do most damage and Rovers failed dismally to do that.
In contrast, Rosenborg were rapier-like when they attacked, carrying far more menace and the fact that they hit the bar with a penalty, struck a post and also forced three splendid saves from Tim Flowers underlines the threat they carried.
Rovers rarely looked as dangerous, except when Ripley was able to get at the home defence and cross to put pressure on a team who didn't look the happiest defending against them.
The only problem was, they didn't have to do it too often. Rovers, frankly, were awful in the first half apart from a superb Shearer strike that had the keeper scrambling. Rosenborg scored after half an hour when Jakobsen's cross was deflected, Jeff Kenna could only head the ball backwards and it fell for Karl-Petter Loken. Flowers could only have been deceived by the fact that the shot was "shinned" and didn't go where it was intended - beating him at the near post.
It could have been all over with 45 minutes on the clock but Ian Pearce's tug on Harald Brattbakk produced only a penalty which Jakobsen blasted against the bar.
Flowers then took centre stage, Roar Strand struck a post and Rovers, enjoying supremacy at last, levelled on 62 minutes.
A rare quality ball in from Tim Sherwood's free kick, after Ripley had been fouled, saw Shearer head decisively down and Newell stab home.
Seven minutes later, Ola By Rise made a stunning save from Shearer's header but, as the first point seemed to be in their grasp, Rovers slipped up.
Pearce allowed Steffen Iversen past him too easily, the slide rule knockback set up Stensaas and the finish was explosive.
Still we await the first win in Europe but there were few moments when it looked likely to happen here.