Wagner was born at Pretoria and attended Afrikaanse Hoër Seunskool as a high school student where he played for the 1st team alongside AB de Villiers and Faf du Plessis.[5] He is a left-handed batsman and left-arm medium-fast bowler who toured Zimbabwe and Bangladesh with South African Academy sides and was twelfth man in two Test matches for South Africa. In 2008, he moved to New Zealand to pursue a career playing Test cricket. In June 2009, he was awarded a place in the New Zealand Emerging Players team under Peter Fulton, and eventually made his test debut for New Zealand against the West Indies in 2012. He played 64 Test matches for New Zealand.
Wagner was born to South African parents but he has New Zealand heritage through his grandmother.[citation needed]
After an uneven start to his Test career against the West Indies and his birth country, South Africa, Wagner established himself as a reliable third seamer for New Zealand side during their 2013 home and away series against England, taking 19 wickets in five Tests. He produced consistent performances over the next two years, including a man-of-the-match eight-wicket haul against India at Eden Park. Despite that, he struggled to maintain his place in the side and was not selected for either of New Zealand's two Tests against England in 2015.
Wagner returned to the side during the Sri Lankan tour of New Zealand in late 2015. He produced a series of strong performances, and New Zealand comfortably won the series. Before the Test, skipper Brendon McCullum described Wagner as his "workhorse".[9]
Those performances earned him another call-up for the second Test against Australia.[10] Wagner bowled well, taking seven wickets including six in the first innings. Since then, Wagner has been a regular starter in the New Zealand Test side.[citation needed]
Wagner continued his fine form during New Zealand's tour of Zimbabwe in 2016, and won the player of the series award. He took 11 wickets in the two-match series, including a five-wicket haul in the first Test.[11] New Zealand then toured Wagner's homeland of South Africa.[12] In the second Test, although New Zealand were soundly beaten, Wagner again led the attack, taking his fourth five-wicket bag.[13]
On 1 December 2017, Wagner became the opening partner to Trent Boult, because Tim Southee was injured, and claimed his best figures of 7/39, which was also a New Zealand record, to claim 7/39 within a day, and within two sessions of play.[15]
In May 2018, he was one of twenty players to be awarded a new contract for the 2018–19 season by New Zealand Cricket.[16] In November 2018, in the second match against Pakistan, he took his 150th Test wicket.[17] In December 2019, in the second Test against Australia, Wagner took his 200th Test wicket, and finished the 2019/20 home season ranked as the number two Test bowler in the International Cricket Council's world rankings.[18]
In May 2021, Wagner was named in New Zealand's squad for the Test series against England and the World Test Championship final against India.[20] He played in all three Tests, finishing the tour with 10 wickets, including three in New Zealand's World Test Championship victory.
