Tottenham midfielder Dele Alli has been ranked the second most valuable U21 player in Europe's top five leagues behind only Paris Saint-Germain forward Kylian Mbappe, according to a new CIES Football Observatory report.
The England international, who has a projected transfer value of £158.5m, is joined in the top five by Manchester City winger Leroy Sane (£109.6m) and Manchester United's Marcus Rashford (£102.8m).
Premier League players continue to dominate the top 10 with Manchester City's Gabriel Jesus (£95.4m), Manchester United forward Anthony Martial (£75.3m) and Tottenham defender Davinson Sanchez (£58.4) all present.
Nigeria international Alex Iwobi (£27.7m) is Arsenal's only entrant on the list of the 100 most expensive U21 players in Europe, ranked the 34th most expensive youngster.
An eye-catching inclusion is Leicester midfielder Wilfred Ndidi (£57m), ranked number 11, while Real Madrid winger and Champions League final goalscorer Marco Asensio (£44.6m) only comes in at 14th.
Chelsea defender Andreas Christensen, who has appeared on 16 occasions for the Blues this season, is among the top 20 and is valued at £41.9m.
England youngsters feature heavily in the rankings with Liverpool's Joe Gomez (£30.1m), Spurs' Harry Winks (£28.8m), Chelsea loanee Tammy Abraham (£35m), Leicester's Demarai Gray (£21.2m) and Everton midfielder Tom Davies (£37.1) all in the top 50.
Watford's Richarlison (£26.9m), who has five goals for the Hornets this season, is among the top 40 alongside former Golden Boy winner Renato Sanches (£32.8m), currently on loan at Swansea from Bayern Munich.
While Manchester United midfielder Andreas Pereira, on loan at Valencia, is among the top 100 valued at £12.8m.
TOP 5 TRANSFER VALUES FOR U21 PLAYERS (CIES)
1) Kylian Mbappe - PSG (on-loan from Monaco) - £161m
2) Dele Alli - Tottenham - £158.5m
3) Leroy Sane - Manchester City - £109.6m
4) Ousmane Dembele - Barcelona - £106m
5) Marcus Rashford - Manchester United - £102.8m