Twice during Sunday's game against Athletic Club, Diego Costa barrelled into the box, a look of determination on his face. Twice he went down, in a heap, and looked up at the referee. When nothing was given on either occasion, he made his anguish clear.
"You know how it is," he said after. "Some referees hate me and there's no way to change it."
Later in the same game, Costa headed over a Filipe Luis cross; he was growing increasingly irascible and frustrated. Athletic had defended well and Atletico appeared bereft of ideas.
But, eventually, Costa's relentless toiling paid off. Kevin Gameiro got the first goal, picked out in space by Antoine Griezmann, and then Costa completed the scoring, bursting through and finishing at the near post past Kepa.
By then, it was clear Athletic's defenders were sick of him. He had been at the centre of everything, a persistent nuisance, an incessant pest. He had done what he does best.
This was a game that, perhaps earlier in the season, Atletico might have drawn. There was certainly a distinct lack of creativity for the first hour and a growing sense that they might be held by their resolute visitors.
In the end, though, it felt like a vintage Atletico win. They had worn down Athletic until the gaps became glaringly obvious and eminently exploitable.
For Costa, such a style of play works perfectly. It is why he proved so effective in his previous spell with the club and why a similarly prosperous return looks likely.
'There is league'
Earlier in the season, when Barcelona looked to be on their way to a comfortable title success, there were complaints that Atletico were lacking something. They weren't scoring enough and were drawing too often. They appeared unusually tepid and vulnerable.
It seemed, too, that they were waiting for something. That, it turns out, was Costa. The aggression, the pugnacity that characterised Atletico has returned with him. They have won all but one of the eight games he has played since and can now consider themselves in a title race. "There is league," as Sid Lowe put it on Twitter.
For a long time it felt like there was no league, like Barcelona would continue to race off into the horizon without so much as a backward glance. Now, though, they are glancing tentatively over their shoulders. What they are likely to see is a glaring, imposing Diego Simeone, waiting to unleash a baying Diego Costa, ready to chase down Ernesto Valverde and his group.
The reality is that Atletico remain underdogs. They travel to Sevilla next weekend, always a difficult fixture, and in early March go the Nou Camp. The odds remain very much in the favour of the Blaugrana.
But there is something about an Atletico Madrid side with Costa at its helm. There are, inevitably, memories of the 2013-14 La Liga title win, secured at Barcelona with a typically dogged draw. Could they do it again?
Their form is encouraging and an attack that had seem stunted now looks far more efficacious. Atletico lacked a focal point; now they have it in Costa, who could be beginning to form an enviable partnership with Griezmann.
The Brazilian-born Spaniard has scored four times in eight games but it was always about more than just the goals. If anything, his return was partly intended to address something intangible: a reversion to the tenacity and ruthlessness that Simeone so craves, and has always been epitomised by Costa more than anyone else.
Other forwards at the club, for all their qualities, couldn't provide that: Griezmann, Gameiro, Angel Correa and Luciano Vietto never felt suitably domineering, nor could they provide the outlet, the presence of Costa in attack.
Atletico now feel like they have momentum and purpose, both of which were lacking earlier in the season.
This was a campaign that began with a transfer ban and the tumult of a stadium move. Simeone's side went out at the group stages of the Champions League and appeared to be out of contention in domestic competition, too.
But the gap to Barcelona is now only seven points, Atletico's defence is typically imperious and Costa is again leading the line, looking to regain the title he helped win before departing to Chelsea.
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