Kristoffer Ajer played his first game of football at the age of six. Raelingen, his hometown club, won 30-0 and Ajer was responsible for 26 of the goals.

“I remember I was refused to play the next matches of the tournament if I could not prove my age,” the defender recalled.“After this, my mother always had my passport with her when I was playing!”.

It was at Start where Ajer made his professional debut against Bodo/Glimt in the Norwegian top flight aged 16.

On the eve of his 17th birthday, Ajer was made captain of Start, in their 1-1 draw against his former club Lillestrøm, becoming the youngest-ever captain in Norway’s top flight history.

Ajer then moved to Scotland and signed for Celtic after a one-week trial. He later moved to Kilmarnock in January 2017 on loan from the 54-time Scottish champions and made 16 league appearances in Scotland’s top division.

On his return to Glasgow, Ajer became a key part of Celtic’s defence and was rewarded with a first Norway call-up, playing in friendlies against Australia and Albania.

Ajer won three Scottish Premierships, three Scottish Cups and three Scottish League Cups at Celtic as well as playing 18 times in European competitions.

“To walk out at Celtic Park in front of 60,000 people, to live in Glasgow, to win trophies with my good mates – it was a very, very nice time,” he said.

“It’s absolutely like living in a goldfish bowl! It’s 24/7 football in that city. Half the city really, really like you; half the city hate you!”.

He joined Brentford ahead of the club’s first-ever season in the Premier League and made his debut against Arsenal in the famous 2-0 win for the Bees.

Ajer scored his first Brentford goal in a 3-0 victory over Southampton in May 2022.

He scored his second away to Burnley in March 2024 and then a dramatic late equaliser against Manchester United as Brentford came from behind to earn a well-deserved point.

Ajer signed a new contract with the Bees in November 2023, committing to the club until 2028.