Porto president Jorge Nuno Pinto da Costa admits some frustration losing Alex Telles to Manchester United.
The Brazil left-back joined United on deadline day last Monday.
Da Costa conceded: "I am never satisfied when a good player leaves.
"Look, a big sale that I was disgusted with was Hulk and it was a big deal. There are times when we have no other solution. One week before the close of the market, he asked to leave because he wanted to go to Manchester.
"I tried for him not to go, I tried to compensate him even if he stayed until the end of the year.
"With Alex it was not a problem to negotiate. The argument for leaving is that the current coach of Brazil (Tite) only called players from three to four championships. I tried to argue against that because he is currently in the Selecao."
