Real Madrid will not sign anyone in the winter transfer window. Per AS, the decision has been made by president Florentino Perez, who thinks the squad is already too big.
They will not pick up Tottenham's Chrisrian Eriksen, who will then look to move elsewhere. Paul Pogba is not coming either, the player coach Zinedine Zidane pines for the most. One of the problems is that there are already 25 players in the squad. So for a new player to arrive someone would have to leave.
Zidane is short on central midfielders though and has problems putting out a line up with the injuries they have. Against Mallorca we saw that and Madrid paid the price, Casemiro the only pure midfielder starting.
AS say Madrid want Zidane to get more out of the 300m he spent in the summer and trust Vinicius, Mendy, Militao and Jovic more. Isco may leave to get more minutes elsewhere.
It's possible that this is a Madrid strategy not to alert their rivals and make players more expensive if they do go to market.