Removing GND pins on a transceiver-less cyclone V

Hello, I am designing a board with a E5CS5EBA6U23C8N device (Cyclone V). On the left side of the FPGA, most of pins are connected to GND because this FPGA do not implement Gigabit Transceivers. I am willing to leave unconnected the pins normaly connected to the transceiver so that It would be easier to route signals or place decoupling capacitors on the bottom side of the board. Should I?