Smith, 28, puts his WBO light-middleweight title on the line against the Mexican superstar at the AT&T Stadium in Dallas.
Khan was sensationally knocked out by Alvarez in the sixth round of their huge clash at Las Vegas? T-Mobile Arena in May.
It was the Bolton fighter?s fourth defeat of his career after earlier losses to Breidis Prescott, Lamont Peterson and Danny Garcia.
And Khan wants pal Smith ? who trains at his gym in Bolton ? to avenge his latest loss.
He said: ?I want him to win the fight because I want him to get pay back for me.
?In a way if he wins it will be like me winning the fight.
?Because he is from Great Britain, we are from the same gym now and we are friends, so I want him to go get my revenge.?
Unbeaten Smith is the massive underdog with some bookmakers having Alvarez, who has lost just once in 49 fights, 1/9 to win the world-title clash.
Khan has shared a ring with both fighters as he sparred with Smith in the build-up to the Alvarez fight in May.
And he believes there could be an upset in Dallas on Saturday night.
The former world champion said: ?Liam has got a great chance.
?I really believe in Liam because I sparred with Liam for the fight.
?He is strong, he is very durable, he moves well and he can take a good shot as well. He has the tools to put on a great, great fight.
