Anderson was eligible to play for Scotland because of his Glasgow-born grandmother, and was selected by Steve Clarke for their Euro 2024 game with Cyprus.
He pulled out through injury before opting to play for England - helping the Three Lions win the European Under-21 Championship last summer.
Though Liverpool's Harvey Elliott was named player of the tournament - scoring six goals including the opener in the final win over Germany - Anderson stood out to the extent was picked in the best XI.
He featured alongside Bournemouth's Alex Scott in midfield to provide England with a solid foundation - and the Forest player's tireless running was particularly impressive in the 3-1 quarter-final win over Spain.
His injury-time penalty moved England into the semi-finals, where they beat the Netherlands en route to retaining their title in Bratislava.
The summer was to be another platform for Anderson, and he carried his form into Forest's chaotic season.
Despite playing under four managers in a successful battle against relegation, Anderson has been a consistent presence.
In the 3-0 win at Tottenham in December, which moved Forest three points above the drop zone, Anderson created the most chances (three), completed more passes (38), won possession the most (nine) and made more tackles (six) than any of his team-mates.
He impressed staff with his commitment, and regularly talks to coaches to discuss the best way to improve both himself and the team.
His positional awareness has also earned praise, though his work-rate and desire to cover as much ground as possible means he can often tire himself out.
A demanding individual, on himself and his team-mates, Forest view Anderson as having the potential to become a complete player.
"It's been a big two years," said Anderson, who moved from Newcastle for £35m in 2024. "I think I've done pretty well in the time I've been here, on and off the pitch.
"I've matured as a person as well and thanks to the club for giving me that platform, going out there and letting me do my stuff.
"In players' careers, you never know where you're going to be. Moving from your hometown is a big step in your career. It was definitely something I needed to do and it has turned out really well. So I'm happy I made that step."
