I'm assuming he's injured? Not seen anything on the official site, but surely Archie wouldn't have changed the back line after two solid displays?
Interestingly in the programme, Balatoni was saying how he is enjoying playing with Seabourne because he feels more comfortable playing on the right hand side of the two centre backs, yet today with Muirhead back in defence Conrad was back on the left hand side.
Seems strange unless of course Seabourne is injured, in which case, not much of a choice for Archie