[6] Kearns' first involvement with the UCD senior team came towards the end of the 2016 season, when he was named in the matchday squad but remained as an unused substitute in 7 games.
[7] Although he again didn't make an appearance, 2017 saw him take another step closer to the number 1 shirt, as he was second choice keeper for much of the year, remaining an unused substitute in 22 of his side's 28 league games.
[7] He made his debut at senior level on the opening night of the 2018 League of Ireland First Division, in a 2–1 win over Dublin rivals Shelbourne.
With such a young squad, coupled with the mid-season departure of many of the team's better players including Gary O'Neill, Neil Farrugia & Conor Davis, meant the side were in a relegation battle with Finn Harps for the entirety of the season.
[14][15] Speaking on the incident, Kearns denied any deliberate time wasting, stating I was playing the game with an injury and whenever I went down to get treatment, there was no way it was timewasting – it would’ve been pushing it to say it was that, but they were on my case any chance they got.
Nobody was hurt, there was no real malice – there was just pushing and shoving but it was probably a bit unfortunate and naïve on my part..[16] UCD were later awarded a 3–0 win as Bohemians had fielded an ineligible player, the suspended Danny Mandroiu.
[19] Due to the postponement of football in Ireland as a result of the Coronavirus pandemic, Kearns had to wait until 10 August 2020 to make his competitive debut for the club, a 1–0 loss away to Finn Harps in the FAI Cup.