Ethernet connection...

Suddenlink owns my box but if there is an easy solution I'd rather do it myself.

I just had Suddenlink move my modem to the TV area but I need my router a little more centrally located - the next room. I have a single RJ45 pass-through in the wall so I can connect the modem to the router, but I just noticed there is an Ethernet cable from the router to the TiVo.

Can I just put an RJ45 splitter on the modem and run one Ethernet to the TiVo and the other to my router? In case it matters, there is a MoCA connection too.

Thanks,
Cane