By Mike Woitalla in Hamburg

It's not often that the United States produces a player like Pablo Mastroeni, an excellent defender with superb attacking skills.

He was born in Argentina but immigrated to the USA with his family at age 4 and played his youth soccer in Arizona. His ball-winning ability, combined with a clever passing game and fine ball control, turned him into an invaluable defensive midfielder for the U.S. national team.

But those who followed his nine-year MLS career will have noticed his flaws: the rash fouls, often followed by a lash-out at the referee. In 188 MLS games, he accumulated 55 yellow cards and seven red cards.

He had, while wearing the red, white and blue, generally contained the ire and recklessness that marked his club play — until Saturday in Kaiserslautern.

A two-footed studs-up tackle on Andrea Pirlo earned Mastroeni his first red card in 50 U.S. appearances.

''It was a poor error in judgment on Pablo's part,'' said U.S. coach Bruce Arena.

The morning papers showed a picture of Mastroeni sliding into Pirlo's legs, the soles of both of the American's cleats flying into the Italian's feet. The picture resembled a series of shots of studs-up tackles under the heading of ''serious foul play'' that FIFA posted on its Web site to demonstrate the kinds of fouls referees were ordered to punish with red cards at the 2006 World Cup.

Arena said he did not show his players these examples, which included the shirt-pulling that 2006 World Cup referees have been directed to punish with a yellow card, which is how Eddie Pope got his first of two yellows that saw him ejected in the second half, and the elbowing that saw Italy's Daniele De Rossi off.

Arena said his men are professional soccer players who know how to play. They did not need to be shown FIFA's examples to prepare for the directives to referees that have resulted in a spate of cards in this tournament.

Who knows if anything could have been shown or said to Mastroeni beforehand to prevent him from delivering that challenge.

We do know that USA had tied the game by then, was playing a man-up and was dominating. Mastroeni's foul occurred in the Italian half and was completely unnecessary.

The Americans may not have beaten Italy had Mastroeni stayed on the field, but the chances for one of the greatest upsets in U.S. history looked darn good.

Mastroeni had been showing mostly his best side before the ejection, keeping Italian attacking midfielders at bay and putting his teammates into dangerous positions with sharp passes. He also fired a 30-yard shot at the Italian goal that barely missed moments before his red card.

We now await word on how many games the 29-year-old will be suspended for. It will be at least one game, and we don't know if we'll see him again at this World Cup. And that's a shame.