As the summer transfer window comes to a close, Tuesday is deadline day in the UK and Europe.
The Portugal forward looked set to join rivals Manchester City, but a dramatic turn of events last Friday saw Ronaldo persuaded to return to Old Trafford, 12 years after leaving for Real Madrid.
He now just has to put pen to paper to complete his return.
He has until 23:00 BST on Tuesday to sign, which is when the transfer window for the Premier League, English Football League and Scotland closes.
The transfer window for Europe’s main leagues close on Tuesday too, with Spain shutting down at 23:00 BST.
In Germany it shuts at 17:00 BST, while Italy and France close at 00:00 BST.
How can I follow across BBC Sport?
You won’t miss a minute of transfer deadline day on BBC Sport.
A running text commentary confirming all the transfers, discussing the rumours and analysing the best of the business will be live on the BBC Sport website throughout the day.
You will also find regular updates on BBC Radio 5 Live and breaking news across BBC Sport’s social media channels, including Twitter, Facebook and Instagram.
Will it be a busy day?
Premier League clubs have spent £962m on transfers so far, meaning there would need to be some hefty outlays on Tuesday to reach last year’s summer window figure of £1.3bn.
One player who won’t be on the move is England skipper Harry Kane, who was heavily linked with a move to Manchester City, but instead pledged to stay at Tottenham Hotspur.
The highest-profile and most expensive deal of the window may yet come on the continent as Real look to snap up France World Cup winner Kylian Mbappeexternal-link from Paris St-Germain after making a second bid of £146m.
The French club are reportedlyexternal-link attempting to make an incredible last-minute effort to sign Erling Braut Haaland from Borussia Dortmund as a replacement for Mbappe.
There were just 12 Premier League deadline-day signings last year – the lowest total in recent years – so will we see more deals completed this time?
Title-chasing Chelsea may be the busiest Premier League club on Tuesday with possible incomings and outgoings.
The Blues look likeexternal-link they will need to pay the £68m release clause in order to sign French centre-half Jules Kounde from Sevilla with Dortmund interestedexternal-link in a deal for winger Callum Hudson-Odoi.
Everton forward Moise Kean may replace Ronaldo at Juventus, while the Toffees could bring inexternal-link former Newcastle striker Salomon Rondon on loan – and their Colombia playmaker James Rodriguez could return to former club Porto on loan.
West Ham continue to be linked with a permanent move for Manchester United forward Jesse Lingard,external-link who enjoyed a successful loan spell last season.
What deals have already been done this summer?
In an eye-catching window, Ole Gunnar Solskjaer finally completed a £73m deal for Jadon Sancho from Dortmund, as well as a £34m move for France World Cup winner Raphael Varane from Real Madrid.
Premier League champions City may have missed out on Ronaldo, but broke the British top-flight record on a single player by signing midfielder Jack Grealish from Aston Villa for £100m.
And European champions Chelsea re-signed striker Romelu Lukaku from Serie A champions Inter Milan for a mammoth £97.5m, the second highest deal of the window.
Arsenal have spent about £140m on reinforcements too, including £50m to Brighton for England defender Ben White, £30m on Real Madrid midfielder Martin Odegaard and £24m on goalkeeper Aaron Ramsdale from Sheffield United.
The Gunners have also cut £200,000-a-week off their wage bill as Brazil winger Willian had his contract mutually terminated to seal a return to first club Corinthians.
Liverpool triggered the £36m release clause for defender Ibrahima Konate from RB Leipzig, while Villa spent the Grealish cash on astute acquisitions including striker Danny Ings, midfielder Emiliano Buendia and winger Leon Bailey.
In Europe, Lionel Messi did the unimaginable by leaving Barcelona and joining PSG after his contract ended at the Nou Camp.
That deal alone would have ‘won’ the window for the Ligue 1 side, but they also made eye-catching moves for Italy goalkeeper Gianluigi Donnarumma, Spain defender Sergio Ramos and Netherlands midfielder Georginio Wijnaldum… all on free transfers.
Find all the latest football transfers on our dedicated page.