McCoist was reacting to stories which claimed that Northern Ireland international Shiels has been told he is free to look for another club.
The 28-year-old has been dogged by injuries since joining the Glasgow giants last year and has been unable to hold down a regular first-team place this season.
But the former Hibs and Kilmarnock forward is fit again now and was on the bench in the 4-0 win over Dunfermline at East End Park last night. And McCoist stressed that Shiels is very much in his plans for the second half of the campaign now he is available for selection again.
He said: "There's no truth in that rumour about Dean at all. He was on the bench last night against Dunfermline and is in our plans.
"It doesn't anger me. I know not to believe everything I read and hear and hopefully it doesn't unsettle Dean."
McCoist is hoping to strengthen his squad in the transfer window - despite the prospect of cost-cutting measures at Rangers in the months ahead.
But he stressed he would have to speak to chief executive Graham Wallace next week before any business can be carried out.
Meanwhile, McCoist has praised his players for the way they played in the resounding 4-0 win over Dunfermline - a result that sent his side 14 points clear in SPFL League One.
But he refused to accept that his side, who have a game in hand on the Pars, have wrapped up the title with the triumph over the second-placed side.
He said: "I can't say the league is over and I never would say it and be disrespectful to the opposition. But what I will say is that it was a big three points for us.
"We were playing the team closest to us and they were making one or two noises about their game.
"But I felt the better team won on the night, there's no doubt about that.
"I was delighted from start to finish. We were unlucky to only be 1-0 up at half-time and I thought we showed a lot of quality.
"It was like an old-fashioned cup tie atmosphere."
McCoist singled out teenage winger Fraser Aird, who received the man of the match award, for special praise after the victory in Fife.
He said: "I was delighted for Airdy. He has come on a lot this season and has been patient. He looked as though he had been there for a long time and took his goal really well."