The 21-year-old central midfielder is still waiting to make his debut for the senior Blaugrana side, but he impressed for the B team last season with one goal and two assists from 16 outings.
De Vega is due to become a free agent in the summer of 2022, though, and his contract situation has supposedly alerted clubs to a possible swoop.
Tottenham are one of the sides keeping a close eye on developments, according to Sport, two years after they had a €4m (£3.4m) knocked back by Barca.
The report adds that Real Zaragoza are keen to strike a loan deal for the youngster, but Barcelona B manager Sergi Barjuan is not willing to entertain the prospect of a departure under any circumstances.
Spurs continue to be frustrated in their search for a new manager, meanwhile, and former Wolverhampton Wanderers boss Nuno Espirito Santo is now thought to be the leading candidate to take over.
Empoli 
Udinese 
CSKA Moscow 
Rubin 
Slovan Bratislava 
AC Milan 
Sparta Praha 
Atletico Madrid 
Valencia 
Barcelona 
Stade Brestois 29 
Bayer Leverkusen 
Red Bull Salzburg 
Bayern Munich 
Paris Saint Germain 
Inter 
RB Leipzig 
Manchester City 
Feyenoord 
Sporting CP 
Arsenal 
FC Rostov 
Spartak Moscow 
Aston Villa 
Juventus 
Celtic 
Club Brugge 
Dinamo Zagreb 
Borussia Dortmund 
Liverpool 
Real Madrid 
Monaco 
Benfica 
PSV 
Shakhtar Donetsk 
Lokomotiv Moscow 
Dinamo Moscow 
Anderlecht 
FC Porto 
AZ Alkmaar 
Galatasaray 
Dynamo Kyiv 
Viktoria Plzen 
Lazio 
Ludogorets 
Qarabag 
Lyon 
FC Heidenheim 
Chelsea 
FC Midtjylland 
Eintracht Frankfurt 
Manchester Utd 
Bodo/Glimt 
Nice 
Rangers 
Real Sociedad 
Ajax 
Tottenham 
Roma