He's a victim of seniority culture becoming more and more prevalent at Barca. Rakitic won't get dropped but we have to accommodate Roberto. Let's find a sacrificial lamb and hes the easiest one to drop. 
The same thing happened with Thiago and Grimaldo, same thing happening with Denis Suarez and probably the same reason why Alena will eventually realise he will never get solid game time here.
The politics within the club have been rotten since Pep left.
		
		
	 
Not really. Valverde is preserving him for big matches because he provides better defensive capabilities than Roberto. If he realise opponents are always sitting so deep, then he subs in Roberto because the latter provides better offense.
I think its Valverde instruction for Semedo to be more defensive. He isnt quite trained in attack, understandably though.
However, its very true for players like Alena. Even Roberto moved up the ranks. Im just not sure why Alena isnt given that privillege despite showing his potential. He didnt even get any playing time. Thats what I hate abt it.