Cristiano Ronaldo has faced some of the greatest defenders of all time across his decorated career.The Juventus superstar has reduced the likes of Gerard Pique, John Terry, Carles Puyol and Ashley Cole to mere mortals with his unstoppable finishing, dazzling dribbling and bruising physicality.However, Ronaldo hasn't always been the all-powerful footballing machine that he is today and it took three seasons at Manchester United before he became the magician we've come to love.Time spent in the gym and early arrivals at Carrington would ultimately change things, but that doesn't mean that old footage of Ronaldo's rawer and untamed style has somehow disappeared.It's a brand of football that many would argue is actually more entertaining than Ronaldo in his prime, though we can all agree on the fact it wasn't as effective or efficient.

Ronaldo vs AC Milan in 2005

You certainly wouldn't see Ronaldo mugging off Pique, Puyol and co so easily when he was opting for step-overs like they were going out of fashion and crashing to the pitch at the slightest touch.

And perhaps one of the biggest ever wake-up calls that CR7 had to make some key changes to his game manifested itself during the 2004-05 Champions League knockout stages.

In a year where Liverpool would miraculously lift 'Big Ears', United were dumped out in the round of 16 by eventual runners-up AC Milan after suffering 1-0 defeats both home and away.

p1eaa6qqe611f91noa1j5f1fl8133f9.jpg

Facing Maldini, Nesta, Stam and Cafu

The game at San Siro also had the historical significance of pitting Ronaldo up against one of the greatest back fours ever assembled: Cafu, Alessandro Nesta, Jaap Stam and Paolo Maldini.

United were in need of a victory having lost 1-0 at Old Trafford, so Sir Alex Ferguson pinned his hopes of an away goal on Ronaldo and his strike partners Ruud van Nistelrooy and Wayne Rooney.

But long story short, Ronaldo was pocketed by Milan's legendary defence.

The Champions League's Twitter account today posted a clip of Ronaldo coming up against Cafu one-on-one, attempting to school him with step-overs, but simply getting tackled by the old veteran as though it was nothing.

Ronaldo's full individual highlights

The evidence is even more damning in his full individual highlights, though, with Maldini battering him on a regular basis on the right flank during the first-half.

It was clear that Milan were trying to be physical with the United starlet, often reducing him to ambitious long-range strikes or putting in crosses that Stam or Nesta emphatically headed away. 

Clashing with Cafu

Ronaldo's frustration during the game quickly became apparent, too, when - having been tamely tackled once again - he lost his temper with Cafu and became involved in a scuffle that the referee broke up.

So, the moral of the story here is that the young Ronaldo was given something of a footballing lesson from a defence that contained wall-to-wall legends.

But in Ronaldo's defence, we're not sure any player in football history could have stood up to Maldini, Stam, Nesta and Cafu when they were just 20 years old.

However, we don't doubt that Ronaldo used the tough experience as an invaluable chance to learn and who knows what would have happened if that back four ever had to face a prime CR7...

p1eaa6vu421r6m1cnuhmrp0un8fb.jpg