Costa has struggled to rediscover the form displayed when winning the French Open last year but remains a class player who can trouble anyone.
World ranking: 25
US Open best:
4th round (2001)
2002: 2nd round
2001: 4th round
2000: 2nd round
His victory at Roland Garros was a surprise but Costa has always had the game, relishing lengthy baseline rallies with his rock-solid groundstrokes.
It remains doubtful, however, that he can find success away from the clay on which he has won all 12 of his career titles.
Costa relishes playing from the back of the court, exchanging baseline rallies, rather than the more attacking game required at Flushing Meadows.
However, in 1997 Costa reached three semi-finals on hard courts, as well as the quarter-finals of the Australian Open, twice losing to Pete Sampras.
And as recently as March he reached the semi-finals at the Miami Masters, losing to Andre Agassi.
He has not exactly been in sparkling form for most of this year but there have been signs of a resurgence.
Miami was impressive, and his epic run to the last four at Roland Garros showed that Costa still possesses the ability to make the latter stages of that particular Grand Slam at least.