Niland was mainly active on the Future and Challenger Tour . In singles, he won three titles on the Challenger Tour. In 2011 he qualified for the first time for the main draw at a Grand Slam tournament : As the first Irishman since Sean Sorensen in 1977 and 1980, he was in the first round at the tournament in Wimbledon . He lost his game against Adrian Mannarino in five sets, although he was already leading 4: 1 with a double break in the decisive fifth set. He repeated his success at the US Open 2011 , where he also qualified for the main round. However , he had no chance against the top seeded Novak Đoković , with the score 0: 6, 1: 5 he even had to give up prematurely due to food poisoning.
He played for the Irish Davis Cup team between 2000 and 2012 . In 22 participations, he played 35 games. Both in the singles with 16:14 and in the doubles with 3: 2, his balance is positive.
On April 12th, Niland announced his retirement from professional tennis. For a long time he had suffered from a serious hip injury that ultimately forced him to retire from his career.