[6] After one and a half years with Ajax, Kristensen moved to Austria and joined Austrian Football Bundesliga club FC Red Bull Salzburg on a five-year contract.

[7] On 8 June 2022, Kristensen joined Premier League club Leeds United on a five-year contract for an undisclosed fee in the region of £10 million.

[8][9] He joined the team from 1 July 2022,[10] and became Leeds's second confirmed arrival of the summer transfer window, reuniting with former Salzburg teammate Brenden Aaronson.

[8] He made his senior league debut for Leeds as part of the starting eleven in their season opener on 6 August with a 2–1 home win over Wolverhampton Wanderers.

[18] He made his debut for the Denmark national football team on 4 September 2021 in a World Cup qualifier against the Faroe Islands, a 1–0 away victory.