Flegler previously played for the Brisbane Broncos in the NRL, the Prime Minister's XIII internationally, and Queensland in the State of Origin series.

In early 2018, Queensland under-20s coach, Justin Hodges drew comparisons of Flegler to that of former Broncos forward, Shane Webcke.

In round 19 of the 2021 NRL season, Flegler was sent to the sin bin for a dangerous high tackle on Penrith's Isaah Yeo in Brisbane's 12-18 loss.

[9] In September, Flegler was involved in a fight with teammate Jordan Riki after a night out during Brisbane's Mad Monday celebrations.

[19] On 6 September it was announced that Flegler had undergone nerve graft surgery six weeks prior in a bid to fix the issue in his shoulder.