If Manchester United wants to make a real impact in the upcoming transfer season, bringing back Cristiano Ronaldo would be the right move.
As reported by the International Business Times, speculation about Ronaldo has been flying since September, when the Real Madrid star stated he was feeling "sad" for professional reasons.
In a more recent press conference, the winger refused to talk about his contract situation, though he remains noncommittal toward Real Madrid
Ronaldo also talked about his old club Manchester United in that press conference, stating "It's a team that has played a large part in my career. People there know me well and the people I know there have a place in my heart."

From there, Ronaldo returned to talking about Real Madrid and his desire to win there this season.
It seems, from Ronaldo's perspective, returning to the Red Devils is what he wants.
And that makes sense. His career really took off there with a breakout 2006-07 season. He was well loved by the fans, and they would certainly welcome him back with open arms.
This is the kind of opportunity Manchester United needs to jump on.

They've been linked to a number of scorers, but Ronaldo has the most prolific resume of any of them. And now he can bring a veteran leadership to the Red Devils front as well.
The move would give Man United one of the best front attacks in the Premier League.
They're currently on top of the standings with 52 points, but it hasn't exactly been with a balanced attack. Robin van Persie leads the Red Devils with 16 points, more than double that of any of his teammates.

Ronaldo has scored 14 goals in the Spanish La Liga this season. His 0.82 goals per game is better than any other Man United player—van Persie is averaging 0.76 goals a game.
Of course, a deal for a star like Cristiano Ronaldo is never a simple matter, and it really comes down to what Man United has to give up.
Early speculation from Mirror Online has the Red Devils sending winger Nani and keeper David de Gea to Real Madrid, along with a £60 million fee.

Nani wouldn't hurt, as the speedy 26-year-old has yet to make an impact for the Red Devils.
Losing de Gea could be tough, but backup Anders Lindegaard could handle a starting role. The Red Devils would surely give up more goals, but not enough to cancel the scores they'd be gaining.
In terms of salary, Man U has the ability to pay Ronaldo in the realm of £300,000 a week. While other clubs could pay more, none have the history with Ronaldo like Manchester United.

If Cristiano Ronaldo were to return to the Red Devils, now would be the time. There's mutual interest in such a deal, and it would be the right move for all parties involved.

Here's hoping Sir Alex makes it happen.