*Club domestic league appearances and goals, correct as of 19:56, 2 January 2025 (UTC) ‡ National team caps and goals, correct as of 08:27, 5 August 2021 (UTC)
Doohan began his career with Celtic, spending time on loan with Cumbernauld Colts in October 2015,[2] where he made 4 appearances in all competitions.[3] He moved on loan to Greenock Morton in August 2017,[4][5] returning to Celtic in January 2018, having failed to make any senior appearances whilst at Greenock.[6]
After signing a new four-year contract with Celtic, he moved on loan to Ayr United in July 2018,[7] making his senior debut on 14 July 2018 in a Scottish League Cup game against former club Greenock Morton.[8][9] Having played for Ayr for the whole of the 2018–19 season, Doohan rejoined Ayr on loan for a second spell in July 2019.[10]
In July 2020 he was linked with a third spell at Ayr.[11] On 1 August 2020 he signed for Ross County on a season-long loan.[12] With Ross Laidlaw largely preferred in goal, he made only five appearances for Ross County and returned to Celtic in January 2021.[13] He then joined Dundee United on an emergency loan in April 2021 following an injury to their first choice goalkeeper, Benjamin Siegrist.[14]
Tranmere Rovers
In August 2021 he moved on loan to Tranmere Rovers.[15] The transfer became permanent in July 2022.[16]