Diego Costa is hard to handle but Chelsea, Premier League will miss him

It seemed like a strange substitution at the time. Now it looks to have acquired more significance.

There were two minutes left in the FA Cup final. Chelsea needed a goal to force extra time. They removed their scorer. Exit Diego Costa from the Wembley pitch — and now, seemingly, from Stamford Bridge. Two months after that anticlimactic ending, Arsenal and Chelsea reconvene for a rematch of sorts in Beijing on Saturday, minus the same meaning and without Costa, the source of many a disagreement between the London rivals over the past three years.

Spared the start of preseason training to negotiate a return to Atletico Madrid, he seemed guilty of premature celebration when he was pictured partying in his native Brazil and his former club’s shirt at the weekend.

Costa has endured a swift, ignominious descent from crucial to castoff. Costa was dumped by text message, a potentially costly error if it weakens Chelsea’s negotiating position with Atletico — not to mention the clubs who know their needs to sign a striker have been exacerbated — and also an indication that Antonio Conte was no longer willing to let the forward dictate the terms.

But assuming this is it and that there is no improbable comeback, Costa leaves a strange, conflicting legacy, perhaps reflecting the divisive figure who appeared equally capable of proving destructive and self-destructive. That part might be unfair: his 120 Chelsea games produced 59 goals and a solitary red card, even if it is a mystery that he was not expelled more often. An ongoing and unresolved debate is how much control the “wind-up merchant” retained on those occasions when Costa seemed more concerned with getting opponents sent off than scoring.

Costa’s volatility reflected Chelsea’s own in a period when they finished first, 10th and first again. In those trophy-winning campaigns, he was rather more potent before February. In the brief slump of what was then the worst title defence in Premier League history, he was better from Boxing Day onward, but such form was never sustained for a whole season, let alone three. He was one of Jose Mourinho’s best signings and one of those most culpable for getting the Portuguese the sack, the sort of player that opponents love to hate briefly attracted the ire of his own. Costa was even branded as one of the “three rats” responsible for Mourinho’s departure on a banner.

He helped Chelsea win the Premier League twice, a feat beyond many with more consistent records. But he also was a reason why Chelsea did not win the league on two other occasions, even if he was blameless for the first: Mourinho opted not to sign a striker in January 2014, as he waited for Costa to become available in the summer.

It was a sign of his primacy in the Portuguese’s plans, and through that, Costa can be seen as the personification of Chelsea’s short-term thinking — an on-field Mourinho. The manager has famously never lasted four years anywhere but tends to guarantee a title, if not more. Even Costa’s arrival was a reflection of how the immediate is prioritised at Stamford Bridge: Rewind to 2014 and Romelu Lukaku was excelling on loan at Everton. There were reasons to believe the fast-improving Belgian represented the better long-term bet.

Chelsea might yet rue not installing Lukaku as their starting striker, but Costa delivered straight away. He suited the ethos of a club with little patience. The cost of overlooking the future would have been measurable had Lukaku rejoined Chelsea this summer, instead of signing for Manchester United: A man sold for £28 million would have been priced at £75m, a £47m loss. Instead, another putative successor — whether Alvaro Morata, Andrea Belotti, Sergio Aguero or Pierre-Emerick Aubameyang — threatens to be similarly expensive.

Chelsea’s short-term gamble on Costa arguably paid off on the field. It would have also done so on the balance sheet had his mooted £76m move to Tianjin Quanjian materialised; instead, the prospect of a vast profit has disappeared.

When Costa goes, so too will the unwanted element of annual drama. Costa returned overweight for preseason training in 2015, which contributed to his poor start to the season. He wanted to rejoin Atletico last summer and, seemingly, China in January. It felt as though Conte compromised to conjure something from Costa for the rest of the season, while also recognising a definitive break was required to avert a repeat.

Costa could offer high quality in high-stakes games — though he was the scourge of Arsenal, he proved less potent against the other top teams — but invariably felt like he was high maintenance. He was seen as the successor to another temperamental target man, Didier Drogba, but the Ivory Coast international’s first spell at Chelsea spanned eight years. Costa never offered the same sense of permanence.

Chelsea will miss his ability to hold the ball up, his capacity to take on an entire defence on his own and his knack for timely goals. They are less likely to rue the loss of a character whose mood swings meant his capacity to set the tone for his team extended to leading by the wrong example. Yet if Chelsea’s manager and power brokers might be glad to see Costa go, many an opposing defender will be happy to be spared more bruising battles with a snarling, stamping striker.

For allies and enemies alike, it promises to be a quieter season ahead.