Robbie Keane has hitched up his shorts like Fabien Barthez and you can see the black kinesio tape on his hamstrings. He glugs down half a bottle of water and pours the rest of it over his legs. He flops on his back and lets the physio shake out his aching muscles.

Extra time is about to begin in the MLS Cup and the LA Galaxy players are strewn on the ground in a disorganised rabble. The New England Revolution players are all on their feet. If they're tired, they're refusing to show it.

The Revs are eager for extra time. Fifteen minutes earlier they'd equalised after their energetic substitute Patrick Mullins played in their left-back Chris Tierney to score.

Between them, Mullins and Tierney make $170,000 (€138,000) a year. Robbie Keane earns $4.5 million. The MVP of Major League Soccer has to step up. But he looks totally spent.

What we don’t realise is that Robbie Keane has a plan.

The Galaxy defender Omar Gonzalez was the man Tierney skipped past on his way to goal. Gonzalez is worried. As the Galaxy retake their positions, he says to his captain: "If we don't score…"

“Don’t worry. I’ll score.”

In the 111th minute, the Revs clear their lines and push up the field. Keane looks weary as he jogs back towards halfway. But he know exactly where he is on the field. The Galaxy's Brazilian midfielder, Marcelo Sarvas, receives the ball and looks up to see Keane lurking in the space behind the right-sided central defender, AJ Soares.

Little bit faster

Later, Keane says that he’d noticed Soares pushed up that little bit faster than his left-central defensive partner, Jose Gonçalves. He’s been targeting that pocket of space all game but his team-mates weren’t seeing it.

This time, Sarvas sees the space. He hits the ball over the top as Keane spins in behind. The pass and sprint are perfectly co-ordinated and Keane doesn’t need to take a touch. He sidefoots low and hard to the keeper’s left and the Galaxy have the Cup.

At the final whistle, Keane stands in the centre circle, raises his hands and face to the sky and waits for everyone else to come to him. Fifteen metres away, Landon Donovan is doing exactly the same thing. Half the players run to Keane, and half to Donovan.

A tiny figure in a Keane 7 shirt runs onto the field. Keane’s five-year-old son is among the first people to congratulate him. Keane picks him up and lifts him into the air. The Donovan huddle is making its way towards the Angel City Brigade ultras behind the goal, while Keane stands in the midfield talking to his son and his wife.

He’s the game MVP so he has to come to the sideline for an on-field interview. “It wasn’t the best game but at the end of the day it doesn’t matter because we’re the champions again.” The crowd cheers.

Now he seems to realise that he hasn’t yet acknowledged the fans. He makes his way towards the ultras, followed by his son. On the way, he comes face to face with Donovan. It’s the first time the two stars have acknowledged each other since the game ended several minutes ago.

About an hour has passed since the moment in the second half when, with the Galaxy 1-0 up, Keane nutmegged Gonçalves and had the chance to play Donovan in for a simple killer goal that would have given America the ending it was looking for.

But Keane ignored Donovan and hit an off-balance shot too close to the goalkeeper. Every one of the 27,000 in the stadium could see what Donovan thought of that decision.

Thankfully Keane has scored the winner, so the two of them get to hug it out for the cameras. Then Keane detaches himself from the crowd around Donovan and walks up to salute the LA ultras, with only his son for company. The ultras sing: KEANO, KEANO, KEANO.

Nice gestures

In October, Keane insisted that Donovan wear the captain’s armband for the American’s last regular-season home game. “He’s made a number of really nice gestures that have meant a lot to me,” Donovan said.

It’s nearly time for the trophy presentation. Keane’s already got the season MVP award, the game MVP award, and the match-winning goal. Maybe he’ll throw America’s golden boy a bone, and let him help lift the trophy at the end of his last-ever game?

No.

In the Galaxy locker-room the players have cracked open crates of Bud Light and bottles of Korbel champagne and they appear to have thrown most of the drink on the floor, where it has collected in great dirty pools.

The Galaxy coach, Bruce Arena, has taken better care of his personal bottle of champagne and he swigs deeply from it as he sits down at the post-match press conference. "Are we sponsored by this champagne company?" Arena giggles, turning the label away from the cameras.

Robbie Keane joins him at the top table. “Robbie doesn’t speak English so we’re gonna get a translator in here!” Arena cries. The champagne seems to be working its magic. The coach unleashes a torrent of tipsy praise.

“That’s the greatness of Robbie Keane, he scores the goal that makes the difference . . . He should be the player-manager of this team. He’s a special leader, a great player, a real friend and team-mate.”

Keane narrows his eyes and stares into the middle distance with the stony impassivity of an Easter Island head. When it's his turn to speak, he thanks his team-mates and pays tribute to David Beckham for putting Galaxy on the map.

Back in the locker-room, the praise is scarcely less effusive. "He's our rock," says the defender Dan Gargan. "We've been leaning on him for that extra little something all year, and he came through just like he always does. He's a beast. He's got that little extra something."

Beast! Rock! These aren’t the sort of words we’re used to hearing about Robbie Keane.

In Ireland Keane – even at 34 – is still defined by a sort of boyishness. People might say he’s tricky, sharp, a fox in the box. But a beast? A rock? That’s when you realise that in America, Keane hasn’t just scored a lot of goals. He has built a remarkable new persona. In America, Robbie Keane is captain, leader, legend.

The technical standard of the final was poor. Keane’s goal came courtesy of the sort of defensive mistake you’ll seldom see from a team like Germany, or even Scotland.

Smartest player

For Keane, playing against college-boy MLS defenders who earn one-fiftieth of his salary probably feels a bit like being back in under-18 football, when he was always the smartest player on the field. That’s why many people think he’s taken the easy way out. He retreated from the highest level to boss it in a league where he knows he can bully everybody.

But you have to remember that three and a half years ago Keane’s career was sinking. He’d been damaged by the failure of his move to Liverpool, where he arrived thinking he was living the dream, only to find that the manager didn’t want him.

The paradox of Keane is that despite his apparent cockiness, he can be rather vulnerable and sensitive to criticism. Under the sceptical glare of Rafael Benitez, who had no idea what to do with Keane and no interest in working out a solution, his confidence withered away.

When Liverpool sent him back to Spurs, English football stopped taking him seriously. For a player who had always been a star, the sustained indignity of the 2010-11 season – when Spurs loaned him out to Celtic and West Ham – was hard to take.

So much of a player’s success or failure depends on how he is perceived by others. Discarded by Liverpool and then Spurs, Keane was left with no good options in English football.

The Premier League had written him off. The best he could hope for was a three-year contract with Birmingham or Blackburn or some other doomed outfit.

The decision to join LA Galaxy, to become an important player in a less important league, could be seen as Keane deciding it was better to reign in hell than serve in heaven.

Only the charms of the heaven Keane abandoned were abstract at best: the highest level perhaps, but the lowest level of the highest level, and a career path that almost certainly led to the relegation meat-grinder.

The hell was made of sunshine, beaches, optimism, possibility; fans who were excited he was coming, journalists who hadn’t already written him off, defenders who could only concentrate nine seconds out of every 10, and four-and-a-half-million dollars a year. Even more important than that, the move would give him what every emigrant is ultimately looking for: the chance to begin again. The chance to reinvent himself, to start a new life.

He’s done so more successfully than any of the big-name foreign players who went to America before him: Beckham, Henry, Ljungberg, Lopez, Blanco.

The decision led to that moment on Sunday when Keane stood as captain, match-winner and double MVP in front of a stand full of American supporters who were singing his name. Beast! Rock!

Beside him his five-year-old son stood and stared up at the crowd with delight. Did it matter to him that the trophy his father was about to lift was only the MLS Cup and not the Champions League?

“For me, these are the moments you want to share with your family. I get more of a buzz out of that than anything else. To have him around and see us lift the cup . . .” Keane said later.

Who could have looked at the two Keanes on Sunday and still believed that coming to America was a mistake? To see them was to be reminded that sometimes in life, the easier option is also the right one.