The Giants placed Murphy (back) on the 60-day injured list Wednesday.
Murphy was diagnosed with a mid-back disc herniation in February and was expected to miss Opening Day for much of spring training, and his placement on the 60-day IL will ensure that he remains out until at least late May. While Murphy works his way back, Sam Huff will fill in as the backup catcher behind Patrick Bailey, and Christian Koss will claim the open spot on the 40-man roster.