The midfielder who was loaned out by City was expected to return to Coventry when his loan expired on January 16th.
However, the Republic of Ireland international who can name Colchester, Brighton and Arsenal amongst clubs he has played for,damaged knee ligaments in October and is only now getting back to fitness.
Barrett said: "It's a pity the injury came about when I was playing pretty well but I hope to be back soon after building up my fitness."