For most players who play a substantial part of their career at one club, they form a close bond with the players, management and the fans. And for some of them still, they cannot help but feel the pain and frustration when their former club loses - becoming a fan themselves.
And that was exactly the situation for Rio Ferdinand on Saturday. It was the eagerly-anticipated Manchester derby which saw old rivals Jose Mourinho and Pep Guardiola come face-to-face, once again, in the dugout. While Zlatan Ibrahimovic had hoped to inflict defeat on the City boss, with whom the striker endured a tough relationship with at Barcelona.
Unfortunately for the 34-year-old striker, his goal was simply just a consolation for what was a fine performance from City, who were without the suspended Sergio Aguero.
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Kevin De Bruyne and Kelechi Iheanacho got the all important goals for the visitors, while United fans were left frustrated and ruing the three points lost on home soil to their neighbours and title rivals.
While working for Premier League Productions, the former United centre-back's reactions throughout the game were caught on camera. And it's fair to say the 37-year-old looked far from relaxed watching Mourinho's first Manchester derby.
The former United defender, who won six Premier League titles and the Champions League during his Red Devils career, cut a frustrated figure.
But despite the loss for his former club, Ferdinand doesn't have too much to worry about considering it was Mourinho's first defeat as United boss - although it does put them three points behind rivals City and the pressure now on to make sure they bounce back immediately away to Watford next weekend.
Saturday's derby result was a reflection of the Portuguese's recent record against Guardiola, which includes just a single win from their last 10 meetings, losing five.
However, the Spaniard also boasts an impressive record against United, having never lost to the Red Devils as either a player or manager, winning five of his seven matches.
Will Manchester City's derby victory prove decisive in their bid to regain the Premier League title this season? Have your say in the comment box below.