Test debut

Astle was first included in the New Zealand national cricket team's squad in 2012 when he was named as New Zealand's second spinner for their tour of Sri Lanka in 2012.^[5] He made his Test debut for the Blackcaps against Sri Lanka on 25 November 2012. He scored 35 runs in the second innings in a key partnership with Ross Taylor of 107. He took his first wicket also in the second innings by removing Prasanna Jayawardene.^[16] Rather than this debut being the start of a long career for Astle, he didn't play another Test for years and was just one of a number of spinners to go through the New Zealand Test team during an injury to Daniel Vettori.^[17]

Return to international cricket

For the next three years, Astle did not return to New Zealand's national team in any form of the game.^[18] In 2015 he was selected to play for New Zealand A, and in a first-class match against Sri Lanka A took just the second ten-wicket haul of his first-class career. He took four wickets in the first innings and seven wickets in the second innings to finish with eleven for the match.^[19] This performance and a successful 2015–16 Ford Trophy put him back into the selection frame for the national team, and in January 2016 he was named in New Zealand's squad for a series of Twenty20 Internationals against Pakistan.^[18] He made his Twenty20 International debut on 15 January 2016,^[20] and played in the first two matches of the three-match series. He didn't take any wickets and conceded 41 runs from 4 overs across the two matches, so ahead of the final match he was released from the national squad and returned to playing for Canterbury.^[21]

Astle became one of the best players in New Zealand's domestic cricket competitions, both in limited overs cricket^[22] and in the Plunket Shield,^[23] which gave him opportunities to play more international cricket matches for New Zealand. He returned to the national squad in the 2016–17 summer to replace the injured Mitchell Santner. He was the only specialist spin bowler named to play in a two-Test series against Pakistan.^[24] His selection received praise from Pakistan's coach, Mickey Arthur, who said that Astle was an "interesting choice" and an "attacking spinner".^[25][26] Astle played in the first Test of the series, the second of his career, but didn't score any runs and only bowled four overs.^[27] He was then included in New Zealand's squad for the 2016–17 Chappell-Hadlee Trophy,^[28][29] but he did not play a game in the series.^[30]

2017–2019, Injury woes

Astle was part of a New Zealand A squad for a tour of India in 2017, and he was the team's best bowler. In a one-day match against India A, he took bowling figures of 4/22, which former Indian Test batsman Rahul Dravid called one of the best leg spin spells he'd seen in Indian conditions.^[30] In October 2017, Astle was named in New Zealand's One Day International (ODI) squad for their series against India, giving him a chance to make his ODI debut,^[22][31] but during a warm-up match against the Indian Presidents XI he tore his groin just three deliveries into his bowling spell.^[30] He was ruled out due to his injury and pulled from the squad.^[32][33]

Astle returned home, and once fit again he played his 100th first-class match for Canterbury^[30] and was able to re-join the New Zealand ODI squad against the West Indies.^[34] He finally made his ODI debut for New Zealand on 20 December 2017.^[35] His first ODI series was a successful one: on debut he took 3 wickets for 33, using his wrong 'un well and rarely bowling a poor ball,^[35][36] then in the 2nd ODI he scored 49 runs as part of a 130-run partnership with Henry Nicholls, New Zealand's highest ever sixth-wicket partnership against the West Indies.^[37][38] In March 2018, he was named in New Zealand's Test squad for their series against England, replacing Mitchell Santner, who was ruled out due to injury,^[39] and in a day-night Test match in Auckland he took three wickets in the second innings, leading New Zealand to victory. Unfortunately he also suffered a side strain during the match, denying him the chance to play in the next Test match at his home ground Hagley Oval.^[23] Regardless, his form in both ODIs and Test matches was enough to give him a contract for the 2018–19 season with New Zealand Cricket, his first central contract after 12 years of first-class cricket.^[23][40][41]

Astle was one of three spinners, along with Ajaz Patel and Ish Sodhi, named in New Zealand's squad for a series against Pakistan, and ahead of the series he played tour matches in the United Arab Emirates for New Zealand A to prepare and fight for a spot in the team.^[42] After he played well for New Zealand A he took a few days off to recover from kneecap irritation. He was initially only expected to miss the first ODI against Pakistan,^[43] but he was later ruled out of the tour altogether and forced to return home early.^[44] Astle recovered from his injury and returned to first-class cricket in New Zealand, where in February 2019, during the 2018–19 Plunket Shield season, he became the leading wicket-taker for Canterbury, going past Mark Priest's total of 290 dismissals.^[45][46]

Astle returned to New Zealand's national team in February for their home ODI and Test series against Bangladesh.^[47][48] Because of his strong form and Ish Sodhi's struggles, he appeared to be New Zealand's favoured second spinner for the 2019 Cricket World Cup alongside Mitchell Santner, but when New Zealand announced their squad in April 2019 they selected Sodhi rather than Astle because Sodhi had more international experience.^[49]

Following the World Cup, Astle was among four spin bowlers chosen to play for New Zealand in their Test series in Sri Lanka, where he'd made his Test debut seven years earlier.^[50][51]

2020 onwards

In November 2019, Astle was named in New Zealand's Test squad for their Test series against Australia.^[52] He played in the third Test of the series, taking 3 wickets overall in the match.^[53]

Astle was named in New Zealand's T20I squad for their T20I series against Bangladesh.^[54] He only played in the third T20I and finished with his career best T20I figures of 4-13 which included the wickets of Mohammad Naim, Najmul Hossain Shanto, Afif Hossain and Mahedi Hasan.^[55] In August 2021, Astle was named in New Zealand's squad for the 2021 ICC Men's T20 World Cup, where he did not get a game.^[56] He was then selected for a T20 series against India, and returned with unimpressive figures of 0/34 in 3 overs in the first T20 at Jaipur.