He was the number one ranked South African amateur golfer before turning professional in 2005 and then joined the Sunshine Tour by finishing 4th at Q-school. His first victory came at the 2008 Suncoast Classic. His second victory came the following year at the Nedbank Affinity Cup.
In 2012, Roos picked up his third victory on Tour at the Platinum Classic after he defeated Chris Swanepoel and Anthony Michael on the fifth hole of a sudden-death playoff.
He picked up his second Sunshine Tour victory of the year in June at the Lombard Insurance Classic after defeating Justin Harding in a playoff. Roos entered the final round four shots back of Harding but fired a 63 (–9) to force a playoff.
Roos started the final round four shots back but fired a final round 67 to take the victory. Sunshine Tour wins (6) Challenge Tour wins (2) Other wins (8) 2010 Zurich Open.