The forward has been linked with an exit from Arsenal this summer.
Sanchez was one of Arsenal’s star men in the 2014/15 season following a big money move from Barcelona that summer.
This past season saw him struggled to find top gear though, as a lack of form and fitness hindered him throughout.
The Gunners overall poor season has not helped either, as their failure to challenge for the title after a strong start played it’s part too.
There have been rumours of an exit for Sanchez this summer as a result, with German champions Bayern Munich having been named as keen admirers.
Those rumours have come alongside suggestions that Sanchez is unhappy at the Emirates, but Zamorano believes that is far from being true.
"I think that Alexis is recovering his happiness. He looks like a happy guy in Arsenal," Zamorano told Omnisport, reported by FourFourTwo.
"Wenger has squeezed him and he has taken the best of Alexis. This is very important, because when he comes on the pitch motivated, he make the difference.”
Arsenal will certainly be unwilling to see Sanchez should there be firm interest in his services this summer.
He is one of their star men alongside Mesut Ozil, and keeping hold of them is key to the Gunners becoming serious contenders once again.
Indeed, Sanchez is vital to their aims of securing big money signings in the transfer window, with the offer of playing alongside stars such as him a big draw for potential recruits.