Arsenal are among the clubs keeping tabs on Switzerland Under 21 international Eray Comert.
The defender - who has captained the Swiss U21's - was an ever present for Basel this season before picking up a minor injury last month.
He has earned rave reviews for his performances in the Swiss top flight alerting a number of Europe's top clubs.
And Gunners scouts have watched Comert regularly so far this season with a view to a summer move.
Everton also have a concrete interest in the 21-year-old and considered a £7million bid for Comert, who is expected to earn his first senior international call-up in March, last month.
Comert's deal expires at the end of next season and has rejected two extension offers from Basel.
And a number of clubs will look to take advantage of the defender's uncertain future this summer, with Basel set to listen to offers from around £5million to avoid losing Comert for nothing if he does not sign fresh terms.