The 18-year-old midfielder has started all 15 matches in his breakthrough campaign.
Only keeper Neil Alexander and Lee McCulloch can also claim a similar appearance record, which is an indication of the faith shown by the coaching staff in the talented teenager.
Boss McCoist said: "The bottom line is that Lewis deserves to be in the team. We have told all the young lads if they are showing enough in training and in youth matches and reserve matches they will get an opportunity.
"I don't think anyone can deny this has been the case. We have had some great displays from some of our youngsters.
"Lewis has played in all 15 games, which is unbelievable really and we didn't expect that to happen.
"But it's to his great credit that it has happened and he will stay there as long as we feel he is doing himself justice and doing the team justice.
"It's part of the whole experience we are really enjoying – watching the young lads coming into the team and watching them progress.
"They are learning their trade and working on their skills and they all do it very well."
Macleod is set to be back in the middle of midfield for this Sunday's live TV clash with Clyde, which is the start of a vital three-game spell for Rangers.
McCoist added: "We have a series of matches coming up in three different competitions which are all very important to us.
"First of all we have the biggest one, the league match at Clyde, and we have to start getting results away from home.
"Then we have the League Cup-tie against an SPL team in the shape of Inverness and then it's the Scottish Cup-tie against Paul Hartley's Alloa."