At Rangers he would be tasked with helping to restore the club to their former glory, and topple Brendan Rodgers' undefeated Celtic.
But does he really believe this is possible if he takes over at Ibrox to replace Pedro Caixinha?
During his time with Aberdeen he has repeatedly tried and failed to beat Celtic, and was on the wrong end of a 3-0 home defeat last week.
After the game he sounded like he had almost given up.
He told BBC Sport: "You know what, I can rack my brains for what system, what personnel - Celtic, when they are in that mood, will win the game.
"Even though we're trying to be competitive with them and will continue to try to be competitive, the gulf is huge in terms of what they can do and bring to the club.
"And our fight, as much as we want it to be with Celtic, is with the rest of the teams and we'll be ready to go again on Saturday."
Such defeatism will not be accepted at Rangers when the primary objective is to beat Celtic and win the league.
McInnes might have been too badly damaged by his failures with Aberdeen to really believe deep down that he could change it with Rangers.
Expectations will be bigger, and the spotlight more intense. Rangers might not be able to afford to appoint a manager who at present believes Celtic are unbeatable.