Bale put in two sparkling displays against the Serie A giants three years ago in the Champions League, forcing then-Inter right-back Maicon to endure a torrid time.
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He told reporters: "I think Gareth has evolved as player. He is even more threatening now.
"I remember seeing the highlights of Inter-Tottenham, and how Tottenham came back into the game late on.
"Maicon was an outstanding right-back, one of the Brazilian right-backs, so to see a young player like Gareth play like he did against him demonstrates his talent.
"Now, two years on, he plays in a different position. He's become a different player, a bigger player, and a more complete player.
"He's the kind of player who can determine the outcome of a game, as we've seen in recent matches."
Bale will be looking to add to his goal tally of 20 strikes in all competitions so far this season and continue his blistering form in recent weeks.
Villas-Boas also spoke about his decision to leave his position of head scout at Inter under now Real Madrid boss Jose Mourinho to take over at Academica de Coimbra.
He added: "It was a difficult moment of my professional life [to leave Inter]. At that time I was scouting for Jose and I wanted to be a little bit more involved with first-team training.
"Jose had always seen me doing the job I was doing. It was a difficult step to take, but it was probably the right one."