The highly-rated youngster made his full senior debut in Shrewsbury Town's Carabao Cup first round tie away at Leeds United in August 2023, starting in front of over 35,000 spectators at Elland Road as well as recording two League One outings, before arriving at St. James' Park in September 2023.

Hernes scored on his professional bow for the Shrews during an EFL Trophy encounter against Wolverhampton Wanderers at the tender age of 16, ten minutes after his introduction from the substitutes' bench, in August 2022.

Primarily a central midfielder, Hernes was named on the bench for the Magpies' Emirates FA Cup victory against Fulham at Craven Cottage before featuring in a Premier League matchday squad for the first time during Newcastle's 3-1 win against Aston Villa in January 2024.

The Heradsbygd-born youngster made his Newcastle first-team debut in May 2024 during a post-season friendly win against Tottenham Hotspur in front of over 78,000 fans at the Melbourne Cricket Ground (MCG) in Australia before making his first start for the club against the A-League All Stars at the Marvel Stadium two days later.