Celtic's Forrest out of Scotland squad for Wales and Serbia qualifiers
The Hoops winger has succumbed to a back injury which requires specialist attention and will miss the March 22 clash with Wales in Glasgow and March 26 meeting with Serbia in Novi Sad.
"James will miss the Scotland games," said Celtic manager Neil Lennon.
"He may need an injection in his back but we're hoping he will not require surgery. It's a huge loss for us and also very disappointing for the boy.
"James has had injuries on and off all season and it has been frustrating for us all because he is a special talent.
"I think part of it is the fact he's still growing. Once he fully matures physically, hopefully it will all settle down."