The 18-year-old England youth international has hit the headlines in recent weeks after Newcastle launched a bid for him.
Sir Alex Ferguson then stated Morrison had turned down the club's offer of a new deal, with his current contract set to expire at the end of the season.
However, Morrison has now taken to Twitter to insist that he has not rejected a deal.
"I have never 1s [once] turned down a contract off Manchester United," he Tweeted.
Morrison, who is yet to make his league debut for the club but has played in the Carling Cup, has reportedly been attracting interest from Spanish giants Real Madrid and Barcelona.