Tottenham Hotspur head coach Mauricio Pochettino reportedly sent a scout to watch Benfica winger Eduardo Salvio in action last weekend.
The Argentine international played the entire 90 minutes as his side recorded a 3-0 win over Vitoria Setubal.
However, were Spurs to firm up their interest in the 24-year-old, it is unlikely that Benfica would accept anything less than a bid of £25m for his services, according to the London Evening Standard.
The report added that chairman Daniel Levy would only consider sanctioning such a deal if the club recouped much of that fee from player sales.
Salvio joined his Portuguese employers from Atletico Madrid in the summer of 2012.
