Fluminense pledge to retain Wallace
"Nobody came to us about buying him and we will count on him for a long time to come," said Teixeira, a former employee of player rights agency Traffic.
Teixeira was brought in to try and ensure young players are developed and then only sold for a reasonable price, should they need to move on.
The full-back is one of the club's top promises and has extended his Fluminense contract by five years.
Teixeira believes the graduate from the club's youth academy will only improve from now on.
"He can still mature more, but he is only seventeen and has already played several first-team games," said the executive.