It can but you're wasting all the potential off of a GTX 1070 Ti. Also, what is the make and model of your PSU and it's age? You might want to also think twice about buying a used GTX1070Ti, especially if it's been used for mining. They aren't good gaming GPU's if they were used for mining.
If your motherboard has an available PCIe 3.0 x16 slot, you can drop in any discrete GPU onto it.