The Spaniard is being linked with a return to Barca in January as they seek a new fullback signing.
"We have already seen that he's a fan!" declared Mestre to Sport.
"He is a great player, no doubt ... (Arsene) Wenger convinced him and promised something we could not. We could not promise that in two years he would play in the position of Dani Alves."
He added: "In many cases it is good to go grow as players and then come back. Look at the cases of Cesc, Pique, Alba, Denis Suárez ... Hopefully the same will happen with Samper. It is positive to have quality minutes in other clubs.
"It is a dynamic that has always given good results to players who carry our DNA in the blood."