Midfielder Morrison, whose two international goals have come against Wales, suffered a hamstring injury playing for West Brom against Stoke at the weekend.
He joins Ross McCormack, James Forrest and Danny Fox as absentees from the original squad selected to face Wales and Serbia.
Norwich City's Steven Whittaker was called up on Monday to provide cover and now Gordon Strachan has summoned Aston Villa's Bannan to strengthen his midfield options.







