The 18-year-old left his native Norway in 2020 to sign for the Danish side, having previously come through the youth system at Bodo/Glimt.
Schjelderup was quickly promoted to the first team after scoring eight goals in 11 games at Under-19 level in 2020-21 before hitting three goals and setting up three more at senior level.
The teenager then became a fully-fledged member of Nordsjaelland's first team last season, making 23 appearances in all competitions and scoring four goals in the process.
This term, Schjelderup has already made 10 appearances Superliga - nine of which have come from the first whistle - and he has five goals and one assist to his name.
Schjelderup has already earned two caps for Norway's Under-21s, and he has also garnered experience playing as a centre-forward and left-winger on Danish soil.
With his contract expiring in 2024, Calciomercatoweb claims that numerous European clubs are monitoring his progress ahead of a potential swoop at the end of the season.
The report claims that Schjelderup is viewed as the 'next Erling Braut Haaland' in Norway, and Arsenal and Liverpool are among the interested parties.
However, it is Sevilla who have already formalised their interest in the 18-year-old, and Los Palanganas are understood to have come forward with a bid of €4m (£3.5m).
The La Liga club were swiftly knocked back by Nordsjaelland, who have raised their asking price for Schjelderup considerably and are now after a fee of €20m (£17.5m) to sanction a sale.
Juventus, Borussia Dortmund and Inter Milan are also said to be keeping tabs on the Norwegian, with the Nerazzurri scoping out potential replacements for Lautaro Martinez.
In total, Schjelderup has struck 12 goals and set up five more in 49 senior appearances for Nordsjaelland, but he is expected to seek pastures new at the end of the current campaign.
With Schjelderup now a permanent fixture in the team, Nordsjaelland have won six, drawn two and lost two of their opening Superliga games to sit second in the table behind Randers.
The striker was called up to Norway's Under-18s squad for their September friendlies with Iceland and Sweden, registering an assist in a 4-2 defeat against the latter.