The German's tip came after the 25-year-old led the Reds' progression into the fourth round of the Emirates FA Cup with a match-winning header against Aston Villa.
McTominay nodded home Fred's cross in the eighth-minute of our close third-round tie with the Midlanders, and has clearly already made a big impression on Rangnick during the few weeks the pair have worked together.
So much so that the club's interim manager believes he has obvious leadership qualities that mark him out as a future contender for the armband, even though more senior players are currently ahead of him in the queue.