But McInnes said: "We can't think that the job is done and put the tools away. We've got a lot of work ahead of us.
"We are where we are because we have worked very hard and we need to continue that to maintain as high a league position as possible."
St Johnstone have performed well on their return to the Scottish Premier League after a seven year absence and currently occupy seventh place, 13 points better off than bottom club Falkirk.
With the league split three games away for the Saints, a top-half finish is unlikely, given they trail Hearts by five points, but a win over leaders Rangers would breathe new life into their challenge.
"The top-six question won't go away because we are sitting in seventh spot but it's not something we contemplated at the start of the season," McInnes explained.
"The priority was survival. We set a target privately with the players about a group of teams we wanted to finish above.
"We wanted to stay in the league but we wanted to do it with a bit of confidence and style."
St Johnstone lost out at Hamilton on Saturday and a long injury list has taken its toll on a small squad at McDiarmid Park.
"We started okay at Hamilton but we looked like we'd lost a bit of spark," added McInnes.
"We were a bit short in terms of legs, with all the injuries we've had and a lot fixtures in a short space of time.
"We have a good, fit team but I've not been able to utilise the squad the way I would have liked."
Rangers were fortunate to leave Perth with a 2-1 win in October, thanks to a late Sasa Papac strike.
Since then, McInnes's side have lost twice at Ibrox, in the league and on Co-operative Insurance Cup duty, shipping five goals and failing to find the net.
"We've done all right against Rangers this season but we haven't beaten them, so that's our target, although we know it will be difficult," said the former Ibrox midfielder, looking ahead to the rearranged fixture.
"Rangers are really strong just now as they go for the title and they can be quite relentless. We need to make sure they don't get it easy here.
"They are top of the league, they are better than us, so we need them not to play to their maximum.
"And if we can ask them questions, hopefully they will have a game on their hands.
"Rangers coming here is a massive game and whoever's selected to play will be up for it."
Source: BBC Sport
Source: BBC Sport