Real Madrid midfielder Fede Valverde has recalled his past trials at Arsenal.
Valverde tested at Arsenal as a teenager when Arsene Wenger was in charge.
He said: "I have always been grateful to him [Alexis Sanchez].
"When I went to train at Arsenal, Alexis was there and he was one of the few who came up to help me. I will always be grateful to him because, being a nobody, I was well-received by him. He was there to help me when I was a kid.
"As a footballer, he is an incredible player."