Cristiano Ronaldo's sublime performance against former Manchester United defender John O'Shea made the Irishman so dizzy he had to see a doctor at half-time of a pre-season clash, according to Roy Keane.
Former Red Devils favourite Keane has dominated the sports headlines this week, with media snippets from his second autobiography causing quite the stir ahead of the controversial book's official release on Thursday.
One of the more amusing anecdotes from 'The Second Half' relates to the circumstances surrounding Manchester United's decision to sign Ronaldo from Sporting back in the summer of 2003 follow his tremendous showing in the Verde-e-Brancos' impressive friendly victory over their English visitors at the Estadio Jose Alvalade.
Sir Alex Ferguson has previously claimed that Manchester United were actually in talks with Ronaldo for a long time period prior to that match, with only the emergence of rival suitors leading to the transfer being swiftly completed.
However, Keane - who spent 12 years at Old Trafford between 1993-2005 and captained the Red Devils before departing under somewhat of a cloud following a bust-up with Ferguson - joked that it was the ineptitude of O'Shea's performance that helped get the deal done.
"We were playing Sporting Lisbon to celebrate the opening of their stadium," he said in an excerpt of the book quoted by The Telegraph.
"He was up against John O’Shea. Sheasy ended up seeing the doctor at half time because he was actually having dizzy spells.
“The club concluded negotiations after the game and we always joked with Sheasy he had actually sealed the deal by playing like a f------ clown."
In fairness to Keane, after slamming O'Shea for his performance he does quickly hand his compatriot and former international colleague a valid excuse.
“In fairness to him, he was jet-lagged [from America] like the rest of us," he added.
Keane likes Ronaldo
While a number of former Manchester United teammates are exposed to Keane's considerable wrath throughout his latest publication, the 43-year-old actually speaks rather fondly of Ronaldo.
This is somewhat surprising considering that the Portuguese was somewhat immature during his early days in English football and certainly was not the same battle-hardened, physically imposing specimen we can observe today.
Manchester United return?
Away from the revelations surrounding Keane's entertaining exploits, Ronaldo - supposedly unhappy with Real Madrid's summer transfer business due to the sales of Di Maria and Xabi Alonso - himself has been subject to a huge amount of speculation regarding his future in recent weeks.
Manchester United have been heavily linked with an ambitious attempt to reunite their former star with record signing Di Maria, although it remains unclear if this is mere fantasy or a realistic proposition given his current £380,000-per-week wages.
Ronaldo is in absolutely top form at present, with Sunday's hat-trick in the 5-0 rout of lowly Athletic his third in just four domestic matches.
One United supporters' group made their feelings perfectly clear to their former hero by flying a banner instructing him to 'come home' over the El Madrigal during Real's 2-0 win over Villarreal last month.