Diego Costa looked finished at Chelsea by the time 2015 came to an end. Following a stunning first season at Stamford Bridge, the controversial striker went completely off the boil and, according to most reliable sources, wanted out.
The problem was believed to be his failure to adapt to life in London. He preferred the sunnier climes of Madrid and fancied a return to his beloved Atletico. However, it seems that the problem was not our wet and windy weather but Jose Mourinho.
Chelsea dismissed the Portuguese manager midway through December after Roman Abramovich was left genuinely fearing the prospect of relegation. As well as that, he had also lost the support of his first-team stars, including Costa.
So, naturally, the team's performances have picked up since Mourinho's departure. Under Guus Hiddink, they remain unbeaten in 11 games across all competitions. Jiminy Cricket, even Eden Hazard has scored, albeit from the penalty spot against a Championship club.
But Costa's turnaround has been most evident, as Sky Sports recently paid homage to with one of their classic infographics. Using Opta, they pieced together key bits of information to show just how dramatic Costa's return to form has been.
And here it is
Costa hasn't just scored a lot of goals since the turn of the year, but important ones too. Indeed, he scored the winner against Arsenal at the Emirates two weekends ago and bagged an injury-time equaliser against Manchester United on Sunday.
However, he is still expected to push for an exit in the summer. Costa originally moved from Atletico Madrid to Chelsea because he believed he had a bigger chance of winning the Champions League.
Currently 17 points behind fourth-placed Manchester City, it seems inconceivable that Chelsea will compete in the competition next season unless, of course, they win it this year and nab an automatic qualifying spot as a result.
Atletico boss Diego Simeone wants the striker back and, having sold Jackson Martinez to China for big money, has the financial means to do it.