The Chile international continues to see his future called into question as he enters the final 12 months of his contract at Emirates Stadium.
He recently admitted while on Confederations Cup duty that he is “clear” on what his next move will be, but has refused to divulge whether that will be signing a new deal or making a move.
The legendary former striker told SFR Sport: "I think Alexis knows very well what he has to do.
“He's a guy who has goals and ambitions, they're fundamental to making a choice. I think he likes to win.
"What he wants, above all, is to win the Champions League, and I don't think he'll have that possibility at Arsenal.
"He must know that he will be more useful in a bigger team. But it's his decision, his personal choice. Whatever happens, Alexis will be at the level he deserves to be and which he must achieve."
Sanchez has spent three seasons at Arsenal, having completed a £31.7 million move from Barcelona in 2014, and has made 145 appearances for the club.
He has found the target 72 times in those outings, with the 2016-17 campaign seeing him reach the 30-goal mark for the first time in his career.