Robin van Persie was spotted at Carrington on Wednesday ahead of Manchester United's clash against Barcelona the following day.
The Red Devils take on Barcelona at Old Trafford in the second leg of their Europa League play-off. The first leg finished 2-2 and the winners of Thursday's game will be regarded as one of the favourites to win UEFA's secondary men's club competition.
Van Persie visited United's training ground to conduct an interview with manager Erik ten Hag for BT Sport, which suggests he is still a fan of the Manchester club. The Dutchman played for United and Premier League rivals Arsenal during his successful career.
Many fans have pondered where Van Persie's loyalties lie. He dropped a huge hint during an interview with BBC Sport two years ago when he was asked to name the most talented footballer he played alongside during his time in the Premier League.
The ex-striker replied: "[It is] So difficult to name one. I would go for Dennis Bergkamp, Thierry Henry, Ryan Giggs, Paul Scholes, Wayne Rooney and Ruud van Nistelrooy."
Van Persie named four United icons but just two Arsenal legends. He played alongside Giggs, Scholes and Rooney at Old Trafford, while Bergkamp and Henry were his colleagues in London. United hero Van Nistelrooy was his international team-mate.
Do you think Arsenal fans have forgiven Robin van Persie for swapping the Emirates for Old Trafford? Let us know in the comments below!
Van Persie started his career at Feyenoord before joining Arsenal in the summer of 2004 - just after they won their most recent Premier League title. Injuries restricted his progress in London, but he still scored 132 goals in 278 games during an eight-year spell.
Despite Van Persie's goals, Arsenal struggled to win silverware under Arsene Wenger during this period. They won just one FA Cup and one Community Shield, which encouraged their star striker to join Sir Alex Ferguson's United in the summer of 2012.
It was a controversial move due to Arsenal's rivalry with United, but one Van Persie felt he had to take. At 29, his time was running out to win the Premier League title.
Van Persie's decision was vindicated nine months later, as the Red Devils comfortably won the league in Ferguson's final season as manager. The Dutchman featured in all 38 of their Premier League fixtures that season and scored 26 goals to claim the Golden Boot. He was also United's Player of the Year.
Van Persie spent another two years at Old Trafford but only won one more trophy - the Community Shield - following to Ferguson's retirement during the summer of 2013. The forward left English football for Turkish side Fenerbahce and later rejoined Feyenoord.
Many Arsenal fans will never forgive Van Persie for leaving the Gunners for their rivals. A transfer between the two clubs is not uncommon, but it was the manner of the move that really annoyed the Emirates Stadium faithful. Van Persie was undoubtedly their best player at the time.
The prolific striker scored 30 Premier League goals during the 2011/12 campaign to win the PFA Players' Player of the Year award. He also ran down his Arsenal contract - forcing Arsene Wenger into a sale - and said he joined United because of the "little boy inside of me". Van Persie admitted he "should have chosen different words" during an interview in 2020.
"The player wanted to come," Ferguson told United's website while discussing the transfer. "I think that was the key to it all and that opened the door for us. He told the other clubs he didn't want to play for them, he wanted to play for Manchester United."
