Cristiano Ronaldo v Zlatan Ibrahimovic: Portugal against Sweden in World Cup play-off is a battle of the titans "Ibrahimovic doesn't play on his own," insisted Bruno Alves, the Portugal defender likely to be assigned marking duties on Sweden's skipper. Yes, he can change a game in a moment, but he's also got to get the service from team-mates. Then Alves got to the nub: "Denying Ibrahimovic space is the key." And for the home team? It would be 11 against 11, said Alves, although Portugal's XI do have a special one: "If there is one player in our team who is irreplaceable, it is Ronaldo, the best in the world. He can settle a game on his own. Even if Ronaldo and Ibrahimovic, CR7 and 'Ibracadabra', were not towering over the fixture because of their fame, form casts them as accelerating juggernauts, colliding at maximum speed. Last weekend, Ronaldo struck a hat-trick for Real Madrid against Real Sociedad. So did Ibrahimovic for PSG against Nice. Over their last seven matches, across competitions, the pair have scored 25 goals between them, 12 for the six-foot-four Swede, 13 for the Portuguese. Nor are these freakishly prolific streaks. Ronaldo has racked up 62 goals in 2013; Ibrahimovic scored 30 times in France's Ligue 1 last season, matching a 23-year-old domestic landmark, guiding PSG to their first title this century. Real Madrid and PSG, two of the most ostentatious and high-spending clubs in the world, have made these men the sport's highest earners, built their tactics around them and based their corporate strategies on their image. And they are very glad to have done so. For their national teams, occupying such a high pedestal is more complicated, less negotiable. Both Sweden and Portugal are captained by exceptional sportsmen, who both grew up with a self-consciousness about being seen as outsiders. When Ronaldo arrived as a child prodigy at Sporting Lisbon, he stood out because, uniquely, he was from the island of Madeira. Contemporaries laughed at his thick off-shore accent. Ibrahimovic is the son of Balkan immigrants, was in trouble at school, and remains an incorrigible maverick. Their individualism made both stand out. Sir Alex Ferguson, the manager who exported Ronaldo from Portuguese football recalls, in his recent memoir, the moment he first saw him play with unrestrained joy: it was, Ferguson writes, "the biggest surge of excitement, of anticipation I experienced in football management." Leo Beenhakker, the former head coach of Ajax who signed a gangly teenager from Malmo, recalls being struck by how unlike the prototype Scandanavian Ibrahimovic seemed: "You saw him doing things Swedish players had never done before." Once they left home, Ibrahimovic and Ronaldo soared, achieving milestone after milestone in club football. But in the decade since they established themselves as figureheads for their countries, their national teams have declined. Friday's contest is between a side ranked 14th by Fifa, and one rated 25th. Rewind to just under a decade ago and Portugal and Sweden were much more musculer. At Euro 2004, a 22-year-old Ibrahimovic announced himself to a global audience with a brilliantly unorthodox goal, a back-heeled volley against Italy for a Sweden who would go within a penalty shoot-out of the semi-final. Ronaldo, meanwhile, maturely helped Portugal, in front of home crowds, to the final. He cried when his team lost it, 1-0 to Greece. Neither Sweden nor Portugal have gone as far as they did at that tournament since. Their superstar individuals are either keeping lesser company in their squads or casting too great a personal shadow. Ibrahimovic's early Sweden career gave him the distinguished Henrik Larsson - with whom he dovetailed and who he admired - as a striking partner, and the lively Fredie Ljungberg - with whom he quarrelled off the pitch - as a foil. With their retirements, Sweden became more mundane, more 'Ibra-centric'. "Zlatan is a wonderful footballer," says the former Sweden and Liverpool defender, Glenn Hysen. But there have been times when there's been the idea that every ball should go via him and for some periods Sweden have even looked better without Zlatan. The Portugal in which Ronaldo debuted had two or three superstars. It still called on Luis Figo, one of Ronaldo's predecessors as a record-breaking Real Madrid recruit; it had the former AC Milan No 10, Rui Costa, and the country's record goalscorer, Pauleta. Though Joao Moutinho is a midfielder of recognised pedigree, the current squad has fewer icons. Expectation that Nani might emerge as a new Figo on the flanks has long expired. Ronaldo must be that. He must also do what Rui Costa did at set pieces, and provide the goals Pauleta used to. "Ronaldo is a player in a different class," said Paulo Bento, the Portugal coach. And it's an honour to have him. It is also an obligation for any Portugal coach to ensure Ronaldo maintains fidelity. Several of his contemporaries - like Ricardo Carvalho, Deco and Jose Bosingwa - called time on their international careers while still playing at a high level for their clubs, frustrated at the environment. Ronaldo's exasperation with a Portugal who find themselves in a play-off because they could not beat Israel home or away, who would have taken only one point off Northern Ireland in their qualifying group had Ronaldo not struck a remarkable hat-trick to rescue a team reduced to 10 men in Belfast, is sometimes explicit. At Euro 2012, he exhibited it through gestures, arms apread out, fingers pointing to where passes never arrived, colleagues' runs should have been directed. "Cristiano is an obsessive perfectionist," explains Jorge Valdano, who was director of football at Real Madrid when Ronaldo began his career there, a record-breaking £81m signing from Manchester United. At that tournament, Portugal made the last four, and held Spain goalless for 120 minutes. The penalty shoot-out, though, would go wrong. There was confusion over the order of kickers, so that at one stage Nani and Alves were both walking up to take the same kick. Spain had won before 10 kicks were completed, the Spanish players mystified why Ronaldo, an expert from 12 metres, had not taken one. Bento said he had been pencilled in for the fifth. Spain have been Portugal and Ronaldo's nemesis at the last two major international tournaments, both of which Portugal required play-offs to reach. Before the meeting of the two countries in the last 16 of the South Africa World Cup, several of Spain's senior players, some of them club colleagues of Ronaldo's, decided together on a policy in the immediate build up to kick off: Ignore him, don't look at him. They reasoned he would be unsettled by that. Spain won. The Swedes, touching down in Lisbon on Thursday afternoon, will fine it hard to avoid looking at Ronaldo everywhere, or at least his image. He's not just on protest art, he's on advertising hoardings, celebrity magazine covers. But when the Portuguese reach Stockholm on Monday they'll see the same. Ibrahimovic towers not just over his sport, but his country's public life, witness Monday's announcement he is to be honoured on new set of Swedish postage stamps. The maverick as monarch.