I think we need both a defender and a midfielder. Our midfield been struggling lately, and we got no one capable to replace any of the midfield 3, apart from Marrone who came on due to a forced injury to Pepe, Conte has't completely trusted him. Another midfielder who can provide cover and competition to the midfield 3 is welcomed, we can't ride our luck all the time. Marchi hasn't been performing for more than a couple of game, bringing another midfielder will send him the message that if you are not performing, there's someone to take over your place. Off course, the signing has to be quality to do this as well.
Some ppl thinks 8 million on a Lich replacement is a bad deal, but Caceres isn't just coming in for RB, he is coming in for LB and CB as well. For 8 million, a quality signing to cover the every position in defense, i think that's a great deal. With Conte's defensive management, i'm sure he can make a good work out of Caceres if he was too sign for us. Hopefully somewhere along these deals we are able to insert Motta and get rid of him permanently.