Tottenham Hotspur have been told that any move for defender Pedro Porro would require them to trigger his release clause at Sporting Lisbon.
Antonio Conte's side currently sit in the top four in the Premier League, but remain in the market for a new right-back with doubts remaining over Emerson Royal, Matt Doherty and Djed Spence.
However, Sporting manager Ruben Amorim has insisted that one of Tottenham's targets, Pedro Porro, will only be allowed to leave should his release clause - thought to be worth around £39.7m - be met.
Amorim told reporters: "With regard to Pedro Porro, we know that there are players in our team who, because of what they have done, are now wanted by other clubs.
"What I was told is that he can only leave if the clause is triggered. And if the clause is triggered, there is nothing we can do."
The 23-year-old played the full 90 minutes in both Champions League games against Spurs this season, as the Portuguese side went unbeaten against the London side.
