Cristiano Ronaldo broke Bayern Munich's Twitter admin during 2017 UCL | OneFootball

Cristiano Ronaldo watched on from the bench once again as Manchester United slumped to an embarrassing 6-3 defeat at Manchester City.

It has been an incredibly frustrating season for the Portuguese superstar, who, having spent the summer angling for a move away from Old Trafford, has been painfully short of game time.

Ronaldo’s body language on the bench was damning and could find himself spending significant amounts of time watching on from the sidelines.

It is a far cry from the Ronaldo we came to know and love over the course of the previous decade and beyond.

As the cream of the European crop prepare to renew Champions League rivalries this week, the fact that Ronaldo will be watching on from the comfort of his home almost seems wrong.

Year after year fans watched on in awe as Ronaldo made Europe his playground, plundering goals for fun and breaking records left, right and centre.

Cristiano Ronaldo's glory days at Real Madrid

During those heady Real Madrid days, he was simply inevitable, helping the Spanish superpower clinch four Champions League titles, including three on the bounce.

He made a habit of turning ties clean on their head, scoring hat-tricks and crucial goals to dig Madrid out of some pretty deep holes.

Not only that, but he did it against some of the fiercest opposition Europe could fling at him at the time.

Never was that more on show than when Ronaldo single-handedly dismantled Bayern Munich in the second-leg of their 2017 clash.

Despite a first-leg brace from Ronaldo, the Bavarians managed to force the second-leg into extra time before the Portuguese star stepped up and took the game by the scruff of the neck.

His hat-trick was enough to see Madrid through while simultaneously breaking the heart of whomever was running the Bayern Twitter feed that night.

The remarkable series of tweets, which you can see below, show just how unforgiving it could be to face Ronaldo in his pomp.

Each tweet mentions one of the three Ronaldo strikes, with the third clearly being written by a broken and battered soul.

He was just relentless, wasn't he?

Crazily, this sort of thing was pretty commonplace for Ronaldo during those days.

As an opposition fan, you simply could not allow yourself to feel any sort of hope while the Portuguese still stood on the pitch.

Sadly, it seems those days are drifting further and further out of view in Ronaldo's rearview mirrors.