The former Tottenham striker believes the Gunners would be better off looking for alternatives to play up front.
The Chilean has started his last two games as a striker for the Gunners, both in the Premier League and Champions League, having scored the winner in the second leg of his side's play-off against Besiktas last night.
The need for Sanchez to start up front has also been strengthened by a four-month injury to forward Olivier Giroud, who has suffered a broken foot.
But Lineker doesn't believe the 25-year-old operates at his best when he is up front.
Indeed, the former Spurs man thinks his preference to play wide right hinders his ability to play with his back to goal.
"Striker isn't Sanchez's natural position, he prefers it out wide, certainly on the right-hand side of a three," Lineker is quoted as saying by the London Evening Standard.
"I'm sure he can play striker because he's a terrific player but I'm not sure it brings out the best in him.
"He's better when he's facing people and going at them, rather than having his back to goal."
Unless Arsenal sign a new striker before the transfer deadline, Yaya Sanogo will remain their only recognised centre-forward while Giroud is out.
Theo Walcott can play up front, of course, but the 25-year-old is yet to recover from a long-term knee injury.
Arsenal's next Premier League fixture sees them travel to Leicester City - another of Lineker's old sides - where Sanchez may feature up front again.