Cristiano Ronaldo's Old Trafford return wasn't supposed to be like this.

For starters, he should have been wearing the red of Manchester United, rather than Juventus stripes.

That was Ed Woodward's mission when he assumed control of the club's purse strings five years ago - and re-signing the Portuguese international would become something of an obsession for the executive vice chairman.

Yet when the chance truly materialised over the summer, United were nowhere to be seen.

Jose Mourinho claims it was never an option. Others suggest it was the manager's decision not to pursue the five-time Ballon d'Or winner, who would upset the balance of an attack that already has a focal-point in the form of Romelu Lukaku.

Either way, it only goes to support the belief United's recruitment strategy is desperately in need of direction.

And so tonight Mourinho is left to plot a way to silence "one of the best players of all time," believing Ronaldo has transformed Juve into genuine contenders for this season's Champions League.

Those inside Old Trafford, meanwhile, may question how different a troubled season would have looked if the 33-year-old had headed back to Manchester, rather than Turin when finally calling time on his Real Madrid career.

Woodward fantasised about it often enough – but he's not the only one.

Sir Alex Ferguson told Patrice Evra the Portuguese forward would soon be back, just weeks before his own departure.

"He even told me '99 percent, Cristiano Ronaldo will come,'" Evra later recalled. "I was like, 'Wow, we are ready to bounce back and to even win the Champions League again.'"

That Ferguson failed to mention his own retirement plans during that same conversation puts the Ronaldo comments into context. But when Woodward told David Moyes of his intention to bring him back from Real, he was deadly serious – if also naive.

"It's been well documented that we wanted (Cesc) Fabregas, (Gareth) Bale and Ronaldo," said Moyes. "There was talk of Ronaldo when I first arrived."

In his one and only summer transfer window, the Scot ultimately ended up with Marouane Fellaini.

Privately Woodward insisted Ronaldo would never have been sold under his watch – not even for the then-world record £80million Real paid in 2009.

A new record-breaking budget was ready and waiting to splash out him, should he ever become available again, he'd add.

But while there were numerous flirtations, the result was always the same – Ronaldo signing a new lucrative deal at the Bernabeu, and United ultimately feeling somewhat played.

Woodward refused to be drawn in again two summers ago – pressing ahead with the £75m signing of Lukaku, despite sources close to Ronaldo letting it be known he was open to offers.

So when he declared again his intention to leave Real in the immediate aftermath of May's Champions League final, United could have been forgiven for thinking it was another ploy to secure an improved contract.

Where they hesitated, Juve swooped – and as the Italian champions rolled into Manchester last night, they did so with a swagger that befits a side boasting one of the two best players on the planet.

Ronaldo, too, strutted into Old Trafford as if he'd never been away.

"It's a huge thing to come back," he said. "I remember what it was like in Manchester. My history - we won lots of trophies, cups, leagues, the Champions League."

There hasn't been anything like that success at United in recent times.

Tonight's match represents the type of classic European night that used to set Ferguson's pulse racing. But such occasions have been few and far between since Ronaldo was last here as Real sent United crashing out in the last 16 in 2013.

Juve will be United's biggest Champions League tie since the quarter final defeat to Bayern Munich in Moyes' short-lived reign.

At times this season, Mourinho's own tenure has looked in danger of following the same path.

With a title challenge already looking unlikely as they trail leaders Manchester City and Liverpool by nine points, Europe may be his only salvation.

With a reputation built on Champions League triumphs with unfancied Porto and Inter Milan, Ronaldo's warning to his Juve teammates not to take Mourinho lightly may have been well-placed.

Yet, after four Champions League titles in the last five years, he was frank enough to admit, victory upon his return was expected.

"Manchester - they are good team, play at home, it will be tough for us," he said. "We have our weapons. We are Juventus, we know it will be tough, but I think we have chance.

"If we play in a good way, the way the coach wants, we have a good chance to win.

"We have to respect United – a fantastic team, an experienced coach - but I expect and look forward that Juventus will win the game."