Fpga_"PHY" to RJ45 with transformer

I understand, that you want to operate the Pluto-II board (a small Cyclone EP1C3 dev kit from KNJN.com) as an ethernet transceiver without a PHY, by directly connecting the ethernet magnetic to FPGA pins? Can you refer to an existing application?

In my opinion, it can possibly work for 10BASE-T, using a LVDS receiver for RX. But you would at least need to bias the receiver to 1.2V and should provide 100 ohm differential termination for Rx and Tx. Also the a 10BASE-T filter should be used for the magnetics rather than a 100BASE-TX transformer only.