[5] However, Grey then suffered a serious cruciate ligament which saw him miss the remainder of 2011 and the majority of the 2012 season.
[6] Upon his return from injury, he made five appearances towards the back-end of the 2012 Currie Cup First Division competition, scoring one try against the Griffons.
[7] He was named in the Southern Kings squad for their inaugural season in the Super Rugby competition in 2013.
[14] The following year, Grey was included in the South African Kings team for the 2011 IRB Nations Cup.
He was the leading try-scorer in the tournament, scoring six tries in three appearances,[15] including a hat-trick against Georgia.