USA has to work for win over Argentina. Just a reminder gold will not come easily.

Team USA was back in Barcelona, wearing 1992 Dream Team throwback jerseys, which led to another round of the Dream Team vs. 2012 team talk.

But the 2012 version of Team USA having to work for an 86-80 win Sunday over Argentina in an Olympics tune-up shows why comparing the two eras is hard (and why the 2012 team’s style can lead to some close games).

The first minutes of Sunday’s game looked like one of those old Dream Team routs. Team USA had Kevin Durant raining threes (he finished with 7 and a game-high 27 points, he will be the MVP of this team) and started out 7-of-7 from the floor and were quickly up 19-3. The USA had 13 fast break points in the first half. They overwhelmed Argentina.

But the Dream Team faced a bunch of international teams in awe of them who rolled over when the first run came. Those teams never dreamed of a comeback.

That is not Argentina. They roll out five NBA players (past or present) including scrappy veterans such as Manu Ginobili (23 points on the game), Luis Scola and Carlos Delfino. They have grown up together as Argentina’s golden generation, they won the gold medal in 2004 in Athens. And they will not quit.

Argentina ground the game down and executed with their passing (and a lot of step-back threes). They got back on defense to take away the easy fast break points that fuels Team USA. Argentina packed the paint on defense, went under picks and dared the USA to shoot jumpers. Team USA obliged and put up 34 threes in the game (hitting 13, 38.2 percent).

And while the USA would make runs, like they did again at the start of the second half to get the lead back up to 20, Argentina would just grind it back down. All the way down to a 78-74 USA lead with 2:45 left in the game. It took a Durant three, a Chris Paul three and some getting the ball inside for the USA to old on and win. Kobe Bryant added 18 for Team USA.

The USA’s aggressive attacking style that gives them the runs can make them more vulnerable against veteran sides that can handle the ball pressure better and know how to slow a game down.

Argentina is not better than the USA. Neither is Brazil (which led Team USA after a quarter) nor France. But those are good squads that can suck the USA into playing a different style. The USA goes on runs but lets up a little, and these team will not quit.

Then there is Spain, who beat Argentina by 20 a few days ago.

The USA plays Spain in a “friendly” on Tuesday in what should be a preview of the gold medal game in London.

It’s going to be the biggest test of the USA’s small lineup, as Spain starts Pau Gasol and Marc Gasol, then brings Serge Ibaka off the bench. Against Argentina Tyson Chandler was a huge impact in the game — he was +26 after three quarters — and he needs to stay on the court against Spain.

The USA is now 4-0 in tune-up games and what we’re judging them on is style points — are they looking as dominant as we expect and want them to be. Like we remember the Dream Team being. And so far this 2012 team has not always been that, not consistently. Coach Mike Krzyzewski is still playing with lineups (he changed it up again for this one, starting Chris Paul over Deron Williams) and trying out combinations. It’s a preseason game and you’re not playing to win so much as to experiment and see what works.

So you can’t take too much away from a closer-than-expected win over Argentina (USA was 28 point favorites). But what you can take away is that the road to gold in London is not a cakewalk. These teams will not just lie down for the Americans.