Vernon tucked in the winner after a neat turn with 10 minutes to go, but McIness admitted that had the Dons not been suffering a number of injuries, the Englishman might not have been on the pitch.
McInnes said: "There were a lot of qualities required. Inverness have come here on the back of a great start to the campaign and we needed tenacity, determination and perseverance to try and get the job done.
"The big thing we were looking for was a touch of quality, and thankfully Scott brought that. You can see what it means to him, the players and the support.
"He's a popular boy and he's had to look in from the outside this season, but he's a top professional and he's got his reward.
"The fact he scored shows you where we are, as he might not have got on the pitch had Niall McGinn been fit. It's pleasing to see."
McInnes felt his side merited the three points, adding: "I felt it was deserved over the 90 minutes. I thought we were totally dominant in the first half, although the second half was much more even.
"Inverness aren't used to being beaten and they don't like being beaten. They threw everything at us, but that bit of quality won us the game."