On 22 September 2017, Strain signed a 1-year scholarship contract with Adelaide United.[2] 3 months later, he signed a two-year contract extension as a senior player, making him the 30th player to progress from the club's youth team to their senior team.[3]
In June 2022, Strain joined Scottish club St Mirren on a two-year deal, following the expiry of his contract at Israeli side Maccabi Haifa.[5] Ryan left St Mirren in June 2024 at the end of his contract, deciding his future lay elsewhere. His grandfather Gerry Baker played for the Paisley club between 1958 and 1960.[6]
In November 2020, Strain was called up to the Australian under-23 team for friendlies against A-League sides.[8] He made his debut on 17 November 2020 in a practice match against the new expansion A-League club Macarthur FC.[9]
Strain was again called up to the Australian squad in September 2022 for two friendly matches against New Zealand in the leadup to the 2022 FIFA World Cup.[12] He made his debut for Australia in the second game, a 2–0 win, as a second-half substitute.[13]
After missing out on selection in Australia's squad for the 2022 FIFA World Cup, Strain was next called up for Australia for friendly matches against Ecuador in March 2023, following the withdrawal of Aaron Mooy due to injury.[14] He made his second appearance for Australia as a substitute in a loss to Argentina on 15 June 2023.[15] Strain made his first international start in a 1–0 loss to England at Wembley Stadium on 13 October 2023.[16]
↑Jackson, Ed (4 September 2021). "No time to relax for Arnie's Socceroos". Retrieved 19 October 2021. Fullback Ryan Strain is also understood to be battling a hamstring niggle.