Marx was also named best Under-23 player and the top South African in last year’s Super Rugby campaign after helping the Lions finish as runners-up.
The 23-year-old cemented a regular place in the Springboks team last year after making his debut against the All Blacks in 2016 and has won 14 caps for his country.
(Reporting by Mark Gleeson,; Editing by Ed Osmond)
