Provided herein are formulations, methods and substituted tetrahydrofuranyl- pyrrolo[1,2-f][1,2,4]triazine-4-amine compounds of Formula (II) for treating Pneumovirinae virus infections, including respiratory syncytial virus infections, as well as methods and intermediates for synthesis of tetrahydrofuranyl-pyrrolo[1,2-fj [i,2,4]triazine-4-amine compounds.