[2] His biggest accomplishment is reaching the final of Australian Open Doubles with countryman Robin Haase in 2013, where they lost to the Bryan brothers.

[3] In singles, he reached the third round of the 2013 Wimbledon Championships and has victories over top players including Jo-Wilfried Tsonga, Milos Raonic and Mikhail Youzhny.

Sijsling's first success on the ATP tour came in 2011, when he reached the quarterfinals in Metz, losing to Ivan Ljubičić.

At the Australian Open, he teamed with Robin Haase to reach the doubles final, losing to the Bryan brothers.

At Wimbledon, Sijsling had his best showing in the singles tournament of a Grand Slam event by reaching the third round, beating seeded player Grigor Dimitrov in the process.

Igor prepared for the first Grand Slam tournament of the season with two warm-up tournaments, in Brisbane, where he lost in the first round to Nicolas Mahut, followed by the Heineken Open, where he again lost in the first round, this time to eventual finalist Lu Yen-hsun.

The following week he played in a Challenger event in Heilbronn, where he made the final, losing to home favourite Peter Gojowczyk in straight sets.