Danny Welbeck knows what it feels like to stand on both sides of the Arsenal-Manchester United divide.

After spending more than a decade on United's books, the striker swapped Old Trafford for the Emirates Stadium on the final day of the 2014 summer transfer window for a fee in the region of £16million.

After graduating to the first-team under Sir Alex Ferguson's watch in 2008, Welbeck made almost 150 appearances in United colours, scoring 29 goals, two of which were plundered against Arsenal. He also won six major trophies during his United career.

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However, the one that was missing from Welbeck's collection was the FA Cup. United failed to reach the final during Welbeck's time as a first-team player at Old Trafford, falling short at the semi-final stage in both 2009 and 2011.

Welbeck scored in the 2008/09 FA Cup campaign for United, striking in both the third round and the fifth round against Southampton and Derby County, respectively. The now-34-year-old's biggest moment in a United shirt in the FA Cup, though, was when he scored against Manchester City at the third round stage in 2012, helping the Reds win a pulsating tie 3-2 at the Etihad Stadium.

Having dispatched of City, United fancied their chances of going the distance that year. However, they were knocked out by Liverpool at Anfield in the fourth round.

United, of course, are facing a similar sized challenge in the FA Cup third round this weekend, travelling to Arsenal on Sunday afternoon. Welbeck won the FA Cup twice with the Gunners after arriving from United, winning it in his first season at the club (2014/15) and then again in 2016/17.

En route to helping Arsenal lift the trophy at Wembley in 2015, Welbeck more than played his part, scoring one of the Gunners' most important goals - the winner at Old Trafford in the quarter-finals. Returning to M16 for the first time since his departure five months earlier, the current Brighton & Hove Albion forward sealed a 2-1 win for Arsene Wenger's team.

He pounced on an underhit back pass from Antonio Valencia, rounded David de Gea and brought United's FA Cup adventure to an end. Unsurprisingly, it created the story of the night and of the round.

Welbeck, however, did not necessarily enjoy the fact he had scored the goal that dumped his boyhood club out of the competition, admitting: "Manchester United is a club that means so much to me. I'm a fan and it's hard to knock them out."

After starting the semi-final victory over Reading at Wembley the following month, unfortunately for Welbeck he missed the final through injury, as Arsenal romped past Aston Villa, winning 4-0. However, he still qualified for a medal after his contributions in the earlier rounds.

Fortunately, Welbeck was able to start Arsenal's second FA Cup final appearance in three years at the end of the 2016/17 season, helping the Gunners defeat Chelsea 2-1. He did not score that day but he had scored twice earlier in the competition.

But had Welbeck's career taken a slightly different turn before it had even started, he may never have played for Arsenal, nor be the proud owner of two FA Cup winner's medals. That is because before any United fan had ever even heard of Welbeck, City had the opportunity to tie him down when he was a youngster.

Welbeck joined United's academy at the age of eight, two years after being originally spotted by club scouts. Before that, though, City, in the striker's own words, "custard-pied" him, rejecting him the day he turned up for a trial.

"My Dad didn't tell me at the time, it was just before Christmas and he didn't want to break any bad news," Welbeck recalled, speaking back in 2012. "It wouldn't have mattered though. I am one of those people that if you are going to say something, just say it. I take it on the chin.

"Straight after Christmas I played in a tournament for my local side, Fletcher Moss, and that's where United picked me up. I went for a trial and have never looked back since. I was always a Red anyway."

Welbeck has played against City 24 times in his career but has only found the back of the net against them once - that being in the aforementioned FA Cup third round tie for United in 2012. In comparison, he has netted six goals against United - scoring only more in his senior career against West Ham United (seven).

Had City not rejected him as a youngster, it would have been interesting to know how his career would have unfolded. Would he have traded one of the Premier League's elite clubs for another? Would he have scored such an iconic FA Cup goal against a former employer? Would he have won two FA Cups? We will never know.

Welbeck, who will celebrate his 35th birthday this year, has enjoyed a fruitful career, making almost 350 appearances in the Premier League, scoring 73 goals, and played in both the Champions League and the Europa League on numerous occasions, scoring 13 goals across the two competitions.

As much as he hated scoring the goal that knocked United out of the FA Cup almost a decade ago, his decision to leave Old Trafford when did enabled him to become a two-time FA Cup winner.