Strauss stayed with the Central Cheetahs until 2009 when he signed a contract with Heineken Cup champions Leinster Rugby. Strauss made his first appearance for Leinster as a substitute in their Celtic League victory over the Scarlets. Strauss played in his second game a week later as a substitute in Leinster's Celtic League win over the Cardiff Blues.
Since then, his Leinster career has gone from strength, racking up a total of 35 appearances – including 9 in the Heineken Cup – culminating in Leinster's 2nd Heineken Cup victory against Northampton Saints on 21 May 2011. By this stage, Strauss had established himself as a firm fan favourite and his barn-storming loose displays and solid set-piece played an integral part in Leinster's triumph.
In October 2013, Strauss was diagnosed with a heart condition that required surgery, ruling him out for the rest of the 2013–14 season.[2][3] However, he made a surprising early return in Leinster's Heineken Cup round 6 pool match against the Ospreys on 17 January 2014.[4] Strauss retired from professional rugby at the end of the 2017/18 season.[5]
In 2012 Strauss became eligible to play for Ireland, and was named in the Irish team to play against his native South Africa on 10 November 2012,[6] where he faced off in the front row against his cousin Adriaan Strauss.[7]
Strauss made his second appearance for Ireland on 24 November 2012 against Argentina, scoring his first ever international try in the process. Strauss' brother Andries has played in a non-cap international for the Springboks against the Barbarians.
Strauss was named in the Ireland squad for the 2015 Rugby World Cup on 31 August 2015 and acquired Irish citizenship two days later on 2 September 2015, during the same citizenship ceremony as Ireland head coach Joe Schmidt.[8]