Valencia - 30
Darmian - 26
Smalling - 26
Bailly - 22
Rojo - 26
Jones - 24
Blind - 26
Shaw - 21
CBJ - 19
TFM - 18
That's quite a young defense especially since two of them aren't really defenders (Blind and Valencia). They can do a decent job there but they certainly do not have the experience to lead a defence. Rojo plays like an 18 year old. He lack positioning, football brain and is often rash. Jones had been out of the defence for too much to be relied on and he hasn't built the neccessary experience to lead a defense and Darmian has yet to settle in the EPL especially since we changed his role (from WB to RB). Our defence rely heavily on Smalling's experience and leadership. If he's out then our defence will lack a leader. Jones-Bailly, Rojo-Bailly, Jones-Rojo, Bailly-Blind, Bailly-CBJ, Blind-Rojo, Blind-Jones do not inspire me with confidence.
Defences had always relied on leaders. The treble winning season had Stam, Irwin, Johnsen and Schmeichel. The 3rd CL squad had Gaz, VDS, Rio and Vidic. This defence lack leaders. Smalling can be a leader (hence why I mentioned him) but he's no Rio and Stam and DDG is no Schmeichel or VDS in terms of leadership