That came into my head also but I'd say Hendrick's versatility would mean they're not really in direct competition, at the moment anyway. Hendrick hasn't played in a central midfield two since the Glasgow game, when we were missing Whelan and McCarthy. I presume Arter would be most effective centrally?
Clark is left footed too and comfortable on the ball, albeit too comfortable at times! You need to just get over this Delaney thing, he's clearly made his own bed. If form was all that mattered and he hadn't retired then, yes, of course he should be the first centre back on our team sheet. It's not remotely like the Westwood situation on all known evidence, there are a number of really obvious and well documented reasons as to why he's being excluded.