Following news that Ronaldo is close to making a dramatic return to Old Trafford, a reporter for TVI ― Portugal's fourth terrestrial television channel ― sought the views of locals.
A video, which has gone viral on social media, showed the reporter asking a passer-by if he was a fan of the Portugal star.
"Actually I'm an Arsenal fan," he responded.
The Gunners supporter was pressed for his thoughts on Ronaldo playing for his team's old rivals, Manchester United.
He responded: "They are not really a rival as our rival is now Brighton but he [Ronaldo] will play in the same league."
The comments were clearly meant to be a damning verdict of an Arsenal side, who have lost all three of their opening Premier League games. Their latest defeat was a 5-0 thrashing at the hands of Manchester City today, which leaves them bottom of the table.
It is a huge fall from grace for Arsenal, who became the 'Invincibles' in the season Ronaldo first joined Manchester United (2003/04).
However, some football supporters were quick to point out that high-flying Brighton are currently rivalling those at the top of the table after winning their opening two games.
Twitter user @LiamBruce94 wrote: "That's ambitious, Brighton are quite good."
@5tephenTownsend agreed that it was a 'bit unfair', adding: "Brighton are better."
@g_vidyasagar was also left confused. He wrote: "Brighton are in the top 4. What’s he on about?"
@EdwardJP23·thought it was 'disrespectful to Brighton', whilst @notyacoubasylla said it was a 'slap in the face' for the Seagulls.
Other fans were left amused by the video.
@SeagullSimon and @davecauvin both commented that the responded was ''hilarious'.
@KinoTravels91 added: "What a response."
@ffscout_az wrote: "This is class."
"This could be the first time we’ve witnessed on camera a damningly realistic but cool and calm football fan," added another football fan, @MarcusSpeller.