Lee McCulloch scored the only goal as the Glasgow giants edged the Premier League outfit at Ibrox and McCoist says there is now plenty of competition for spots ahead of Sunday's trip to Edinburgh to face Heart of Midlothian.
"I felt really pleased with the shape of the team, especially in the first half, and it's a good build-up for Tynecastle on Sunday," he told the club's official website.
"I knew we would have to work really hard against a team with players of great quality.
"We scored the goal and had chances in both halves which was pleasing.
"I certainly have some thoughts to ponder for the weekend. You hope that when some of the lads are given the opportunity to come in they do well to give you a headache and they have certainly done that.
"I rested a few of the lads with Sunday in mind. I left the two centre backs back, for example. I was going to give Stevie Naismith 45 minutes but he had a little bit of sickness.
"Sunday is obviously far more important and we have seen in recent weeks that Tynecastle is a tough place to go but it's a place we enjoy going to."