The last time Barcelona met Manchester City at the Etihad, Barcelona parked the bus. Then Yaya Touré clambered on board. According to Víctor Valdés, he spent “two hours” taking photos and greeting old friends. Twelve months on, Barcelona are back and although Touré’s first-leg suspension means they won’t see him on the pitch, they will be waiting for him by the bus – and none more so than the man who helped push him out of Camp Nou in the first place.

Sergio Busquets, 26, does not see it exactly like that, of course. He insists that Touré’s departure was no “victory” and the warmth is genuine. But he does concede that it was important, proof of the faith Pep Guardiola had in him. Touré had won two leagues, the Spanish Cup and the European Cup, and is not a footballer you let go, even if he pushes to leave; not if you don’t have an exceptional replacement.

Guardiola was convinced he did. Touré left on 2 July 2010, for £24m. In eight months Busquets had gone from playing at Santa Eulalia, in Spain’s fourth tier and at a ground holding 1,500, to the 2009 European Cup at the Estadio Olimpico in Rome; a year after that, he had won his second league title. He usually played ahead of Touré but this was another step, the responsibility now his alone. He was 21. Nine days after Touré joined Manchester City, Busquets was a world champion.

“People were surprised because Touré was one of our best players, but I knew what was going through his mind,” Busquets says, sitting at Barcelona’s Sant Joan Despí training ground. “Ultimately, players choose their destiny and he chose to leave. He could have stayed, but I’m sure City told him he’d play more and earn more; it wasn’t that Barcelona wanted to sell.”

Nor, though, did they block his departure. Touré has proved a bargain for City, outstanding in two league titles, and they would happily have him at Camp Nou. But, although questioned at the time, his departure is not looked back upon with regret or recrimination. Instead, most consider the decision vindicated – because of Busquets.

On one level, that may appear odd. Touré has scored 61 times for City; in six seasons Busquets has never got more than a single league goal, and he does not provide assists either: none so far in all competitions this season; three last season; two the season before; one the season before that. He is not an extraordinary athlete, fancy flicks are few, he neither excites nor stands out, and headlines are rarely his.

It would be understandable if he sometimes wished they were, if he craved the glory of goals, but the response is swift: “No, no …” He skirts criticism as quickly; the dirty player or cheat in your rivals’ team would be a hero in your own. He admits that football’s “not a bed of roses”, hard to imagine for those who “haven’t been in a footballer’s skin”, but he seems relatively removed from the pressure it brings.

“I don’t want people talking about me, for good or bad. I don’t do many interviews. I don’t have Twitter. As kids we’d be forever shooting at dad [the then Barcelona goalkeeper, Carles] and I started as a striker. But I eventually became a pivote, the position I like most and best suits my characteristics. Forwards get the plaudits and goals are football’s essence. But I’m not selfish like that, I don’t long for praise or the lead role. I’d rather the strikers scored [than me]; they live off goals. I don’t care. If I did, I wouldn’t play in this position. I love my role, I love the job I do.”

Appreciative colleagues do too. If there are those who do not particularly rate him, and others that dislike him, those who have worked with him are not among them.

He squirms slightly when the eulogies are quoted: Johan Cruyff said he was “a gift for any manager” and his managers agree. Guardiola said he was “priceless”; Luis Enrique describes him as “almost perfect”; Vicente del Bosque claimed that if he could come back as any player it would be as Busquets.

Xavi Hernández called him the “snowplough”, clearing all before him. Since 2010, only Dani Alves has made more tackles at Barcelona, but he is not the stereotypical muscular figure flying into challenges that puts opponents on their backsides and fans on their feet. If the tackle count is high, and the nastiness matters, the pass count is higher, trailing only Toni Kroos in Spain. And he doesn’t run box to box. At times, he appears hardly to run at all, defined more by patience and pause.

Few midfielders wait like him, seemingly inviting danger that rarely materialises. It is no fluke. When he first emerged, up in the stands they suffered a collective coronary; down on the pitch he barely flinched. “I don’t get nervous. From the outside it can look too long … but options open if you wait,” he says, laughing. “Well, usually.”

“Tactically, he’s incredible,” says Gerard Piqué. He is the kind of midfielder rarely made in England, a different concept: intelligence over athleticism. Less a defensive midfielder than the pivot upon which everything depends.

“English football’s more about intensity, physicality; here it’s more tactical,” he explains. “The pivot is more about being tactically astute than physically dominant: thinking, calculating, offering solutions, defensively and offensively. Control everything.

Positioning is key. Barcelona’s style means that defensively you deal mainly with counter-attacks – not stopping them, preventing them. If you defend high, it’s a long way back towards your own goal, so you need to prevent those breaks.”

This year has seen a shift in style, though: more mixed, more direct, more aggressive, more open, willingly trading blows. When it is suggested that Barcelona have rediscovered their “balls” too, Busquets nods. A team defined by their midfield, that once played 3-7-0 in the World Club Cup final, are now defined by the forwards. Around him, the game is changing and the evolution has not always been easy.

“There were new signings, a new coach,” he says. “Also, at first under Guardiola, teams didn’t give us so much respect; they played openly. Now 95% of them wait, shut down, and counter-attack. It’s more difficult to play one-touch [so the new style] is partly a reaction to other teams. It’s a mix now. Team-mates are not as close to me, which has advantages and disadvantages. There’s more space and a lot more counter-attacks. We have players that can change the game. Messi, Neymar, Suárez …”

“Luis [Suárez] embodies the shift. He gives us a lot. The numbers [of goals] are not the same as at Liverpool but Barça play differently. Our reference is Leo, we know that and players arriving here know that. Luis has given us much more power: the difference is very noticeable and he’s a big reason why Neymar and Messi are playing so well – not just them, the whole team.”

Suárez is the Busquets of the forward line then, working for others, getting his hands dirty while others take the glory? “Well,” Busquets says, “there’s something in that, I suppose. I’m sure Luis is happy. Outside voices might say ‘Suárez has to score more’, but I don’t care about that if he works like he is, defensively and offensively, his movement is good, he creates spaces and the team scores.”

Largely, it is working. Barcelona’s surprise 1-0 defeat to Málaga on Saturday came after a “crisis” at the turn of the year was overcome with 11 consecutive wins. “Things were in the air a bit before but we’ve reached this point in good shape physically and tactically,” Busquets says. “We’re contenders: the league, semi-final of the Cup, last 16 of the Champions League.”

There City await. It is easy to imagine Barcelona’s players cursing the draw. Busquets smiles: “Of course. Everyone’s there on merit, but, yes, some teams are stronger. Mostly though, when the balls are drawn and it’s the same team again … it’s boring.”

Except that it is England, and here Busquets becomes animated. Asked if he envies the freedom midfielders have to tackle compared to Spain, his reply is surprisingly emphatic. “I envy everything. I admire the Premier League for the quality and style of football. Maybe after years playing the same style you tire of it, and football there is very different. Stadiums are full, pitches are good, the press is different, people are different, the football culture is different. Everyone talks highly of England and I’d like to experience it one day. You see more space, more opportunity to enjoy your football. It’s more physical, more intense, but I think I’d be comfortable. I can’t say I’ll definitely play there because things change and I’ve always said I want to stay here for many years, but I’d like the experience.”

What, then, of City? Busquets says he watches fewer games on television than he did – “well, I’ve got a girlfriend now,” he shrugs, smiling – but he has watched City and, for him, watching means really watching.

“Even if you’ve put the TV on for fun you end up analysing how they’re playing, watching the player in your position, wondering: ‘Do they play more direct? More slowly? Do they use the wings? Who are the two or three players they go through?’ City play good football and are not a team that tries to suffocate you. On the one hand, we’ve drawn a tough opponent; on the other, they let you play, which might help.

“But they’re creative and dangerous, especially when the ball reaches [David] Silva. He’s the player, with freedom of movement and his final ball.

“They have others who can unsettle you too, like Kun Agüero and Jesús Navas, who’s so quick. And there’s Yaya … not this time, but in the second leg.”

This time will see Touré by the bus. “I learned from him. He was a great team-mate from the first day until the last. I never considered his departure a victory and we still get on magnificently.

It can be one year, or two, or five, but the relationship you build is special. Players pass through, but friendship remains.”