A year ago, it didn't make sense for Madrid to buy Paul Pogba. James Rodríguez was an undisputed starter and therefore the French midfielder didn't have room in Madrid's midfield. However, Los Blancos are considering making a move for Pogba now that James appears to be on his way out of Madrid.
Zinedine Zidane wants to sign the Frenchman and James would be an expendable asset to get a cheaper deal agreed with Juventus. Toni Kroos would be playing defensive midfielder again with a more physical player in Pogba playing upfront and pressing the opponent.
If that happens, Casemiro and Isco would be reserves waiting to get some minutes depending on the characteristics of the game and what the team needs, barring some injuries that could also happen to give them plenty of minutes in what will be yet another long season for Los Blancos.
Either way, it makes much more sense to go after Pogba and Madrid could make an effort to secure the midfielder, a player Zidane thinks could make a big impact on the team.