Amid the uncertainty over the club's next manager and the general lack of stability within the hierarchy, Terry had become disillusioned with the idea of playing for the West London club.
It wasn't just the fact that Chelsea faced losing arguably one of the world's best defenders, but one who had made over 400 appearances for the club and was a product of their own academy.
The very idea of selling Terry to Manchester City, Chelsea's closest challengers in terms of financial power, was one that frightened the senior figures at the club, which resulted in them trying desperately to cling on to their prized asset.
A sale to the Citizens was simply not an option.
There was also the case of money. Frank Lampard, Didier Drogba and Michael Ballack were all on higher salaries than Terry and, as a result, the former England international wanted equal parity, according to the Telegraph's report at the time.
Eventually, Terry got his wish: a new five-year deal worth £160,000 per week which underlined his importance to the side. Since then, he's never looked back.
Another Premier League title followed the same season, as well as two FA Cup medals, a Europa League medal and, most importantly, the chance to hold the Champions League winners' trophy in that four-year period.
It's fair to say that Chelsea's success—and, therefore, Terry's trophy-laden cabinet—has been a result of the sheer quality of managers who have taken the helm at Stamford Bridge. Mourinho is most notable among them, but even coaches such as Carlo Ancelotti and Guus Hiddink have left a visible impression on the club and Terry, enabling him to improve as a player.
The Barking-born defender has earned his right to success, with a reputation for being one of the toughest defenders in English football's recent history. It goes hand-in-hand with the amount of passion he has for the game, and of course, for Chelsea, and that determination contributes to the fact he puts in 100 percent every single game.
You only need to ask Jose Mourinho why he enjoys such a close relationship with the former West Ham trainee, who provided an excellent example of how the older players, including Terry, still show an insatiable desire to work hard on the training pitch.
He was quoted by the Daily Mail as saying: "When I see Terry, Cole, Lampard and the way they are working at 32, 32 and 35, it's easy for me to control the group and demand the same from the other guys. I can say: Look that them. They don't miss one minute. They are training like animals. They compete. So you, who are 18, 19, 21, don't tell me you can't do it."
The main point to take from Mourinho's words is the way Terry leads by example. The captain is known to enjoy lighthearted fun with new recruits off the pitch, but takes his work very seriously on it, demanding that his teammates play to the best of their ability as he does.
His level of aggression and determination is impressive, but his timing of challenges is even more so. If there's an aerial battle to be contested, the towering centre-back ensures he rises above his opponent. If a ball is loose, Terry will never pull out of a tackle.
He may come out of it worse than he went in, but that's all part of his heroic character, which makes him a worshipped figure at Stamford Bridge.
Another aspect of his play which has yet to falter is his reading of the game, and thus how he adapts his position to what he sees. At 32, he is certainly not the fastest of defenders and, as a result, he has to model his game based on what he capable of doing.
The sheer organisation in his game is astounding, too. You'll often notice that Terry is the man who goes up for most aerial challenges, and in doing so, leaves either one of Gary Cahill or David Luiz trailing behind him. That's because if he fails to win the header—and that is a rare occasion—one of the two faster defensive partners can chase the ball behind him.
That level of organisation is often so rare in defenders these days. It gives some insight as to why Chelsea conceded more goals without Terry in the side, and perhaps reflects why Rafa Benitez came under fire for continuously leaving him on the bench.
Of course, like every player, there are some obvious drawbacks which have even led to Mourinho refusing to guarantee the veteran defender a regular place in the side.
On the club's tour in Kuala Lumpur, he told reporters: "John is not safe, he knows he's not safe. Professionally speaking, no one is safe," per the Mirror.
Whether this was a ploy to get Terry to play to his brilliant best this season is something only the Portuguese mastermind will know, but there's no doubt it will have the desired effect.
Mourinho knows he can no longer rely on Terry or Lampard to play 38 games a season, and must use the two sparingly and only when required. Lampard's fitness is near perfect, but Terry's injury problems continue to mount.
He missed a chunk of the 2012-13 season after a late challenge from Luis Suarez on the knee in the 1-1 clash with Liverpool, and missed the Europa League final due to an ankle injury sustained against Aston Villa.
Because of this, his reliability and fitness is always in doubt, and while attackers used to fear coming up against the former England defender, it's now a less daunting prospect.
That said, his solid showing against Hull City on Sunday was a reminder that he still has a huge part to play in Chelsea's season.
And if he helps the Blues secure the Premier League title in May, perhaps he can return to the "world-class" bracket for good.