Van Persie has been strongly linked with the likes of Manchester United and Manchester City after having scored 30 Premier League goals for the Gunners this season.
"He's amazing," Santos told ESPN Brasil. "Besides being a great person, he is also one of my best friends at Arsenal. He is a guy who has given me full support.
"He is very intelligent on the pitch. He smashed the Premier League.
"It helped Arsenal get to where we are, in the Champions League spots, and I have no doubt that he will be one of the stars of Euro 2012.
"He has been at the club eight years and this was his best season.
"Sometimes, a player is interested in getting to know other teams and of course, playing well, he has attracted interest from many other teams. Of course your mind is affected.
"He is currently fully focused on the Euros and then, after, he can talk about whether he wants to stay with Arsenal."