Impey was drafted by Port Adelaide with their first selection, pick 21, in the 2013 AFL draft. He made his AFL debut against Carlton in the first round of the 2014 season. Since making his debut, Impey has been used a back pocket shut down roll on small forwards. Impey has had mixed results but has been successful against the likes of Hayden Ballantyne, Eddie Betts and Jay Kennedy Harris. In round 8, 2014, Impey was the Rising Star nominee for his defensive performance against Fremantle's Ballantyne.[4]
The start of Impey's 2015 season was curtailed by a hamstring injury, however he only missed one game after returning from injury in round 7. His development into a small lock down defender continued for the rest of the season and in the round 12 match against Carlton he recorded a career-high twenty-three disposals and a season-high four inside-50s.[5]
2016 saw Impey move into Port Adelaide's forward line where he excelled as a small forward with a series of elite performances including three goals against Richmond to lead the Power to victory. He capped off his first season in the forward line by winning the Gavin Wanganeen Medal as Port Adelaide's best player under 21.[6]
Impey was suspended by the club for an off field indiscretion during the summer break and missed round 1 of the 2017 season but bounced back with a handy contribution of nineteen disposals and one goal in round 2 against Fremantle.[7][8] The round 6 match against the Brisbane Lions saw Impey kick a career-high four goals.[9]
^The 2020 season was played with 17 home-and-away matches per team (down from 22) and 16-minute quarters with time on (down from 20-minute quarters with time on) due to the impact of the COVID-19 pandemic.