Diego Costa has won two Premier League trophies in three years at Chelsea. He played an integral part in both triumphs. In his debut year, he scored twenty goals as Chelsea strolled to the title. In the campaign just passed, Costa repeated his feat of twenty league goals with similar success. Yet, despite his contributions, the Spanish international has failed to settle in England, and his relationships with both of his non-interim managers has been sketchy at best.
His fall-out with Jose Mourinho was well publicised, and played a part in the manager's dismissal halfway through the 2015-16 campaign. Costa was a shadow of the player that took the Premier League by storm the year prior, and his poor performances were a huge reason why Chelsea endured the disappointing season they did. Of course, Costa isn't the only one to blame, but it does play into the storyline surrounding Costa's time at Stamford Bridge.
His inconsistency and unreliability was at constant odds with his pure finishing ability and superb link up play with his teammates. Chelsea never really knew which Costa was going to show up for them. And that was never going to sit well with such a fiery character as Antonio Conte.
Costa started the season like a man on a mission, keen to prove his doubters wrong and repay his believers. One of the latter seemed to be his new Italian manager. After each game the duo shared a warm hug in celebration of victory, and after scoring against Crystal Palace at Christmas time, Costa made it a note to celebrate his goal with Conte. The relationship seemed strong, and the forward was enjoying life again. And then came January.
An offer to become the latest high-profile player to join the riches of the Chinese Super League seemed to have turned Costa's head. After his great first half of the year, the 28-year-old was now distracted by the speculation. It led to a heated argument with Conte, who reportedly told him to "F*** off to China!". The result of the bust-up was an absence from the team bus for the away match at Leicester. Chelsea won comfortably, but the message was sent loud and clear to Costa. If he didn't want to be there, Conte wasn't going to beg him to stay.
In the months that followed, Costa was showing signs of another disappearing act, very much like the one we had to put up with in 2015-16. He led the way for the 13-game winning streak that put the Blues in a strong position for the title, and yet it felt like Chelsea were now going to win the league in spite of Costa, not because of him. His performances were poor, his determination and fighting spirit that was so obvious earlier on in the campaign was nowhere to be found and calls for him to be dropped soon emerged.
His on the field antics annoyed some, but others revelled in it. They were seen as a sign of his passion and commitment to the shirt, and though his actions were questionable, his intentions seemed to be on point. The fans saw Costa's "dirty" side as his way of showing how much he wanted to win games. He'd annoy and hassle opposition defenders, in hopes of provoking a reaction (see: Gabriel in 2015) or to distract them. It wasn't always pretty, but as long as the goals kept coming, there didn't seem to be a problem.
It's when those goals started to dry up, and he focused more on his antics, that supporters grew restless. He wasn't working for the team, and made it feel like Chelsea were playing with 10 instead of 11. He did manage to find the back of the net a couple of times towards the end of the season, and even scored the equaliser in the FA Cup final defeat. But the damage had been done. For the second year in a row, Costa let it be known to the fans that he couldn't be depended on week in, week out.
The latest episode in Costa's controversial time with Chelsea has been just as messy and dejecting as the ones before it. Text messages and press interviews have been used as methods for management to let Costa know he's not wanted, and for Costa to then let the world know he's not wanted. It's very unlikely we ever see him suit up in a Chelsea kit again. And what a shame. Costa brought trouble and attracted the wrong sort of attention. But on his day, when football, and not silly bickering with opponents, was his priority, he was one of the best goalscorers the Premier League has seen.