Schalken was one of the players to emerge from the higher reaches of the top 50 and really make an impact last year.
World ranking: 12
2001: 3rd round
2000: 3rd round
After eight years as a pro, the tall Dutchman had his best season to end the year 20th in the Champions Race.
A poor opening six months was turned around last summer when he made the final four at Queen's and the last eight at Wimbledon, winning on home soil in between.
Even more impressive was his run to the semi-finals of the US Open, where only a rejuvenated Pete Sampras could stop him, and another final followed in Moscow.
Schalken may not be the most elegant of players - few look as awkward from the back of the court, due to his stiff-backed technique - but he is strong off both sides and has a huge serve.
He has proved he has what it takes to progress in Grand Slams and, having reached the quarters last time around, could push for another strong finish this year.
Schalken is no stranger to marathon matches at Wimbledon. In 1999 he was knocked out by Jim Courier 13-11 in the deciding set.
And a year later he took part in the longest ever final set in Wimbledon men's singles history when he lost 20-18 to Mark Philippoussis in the third round.