"Clive has already said that and the players know that," he said, although he added: "Martyn Williams has been playing well right through and Gavin Henson played well tonight."
However McGeechan was certain any players left out would continue to support the squad.
"That's been the big essence of everything so far."
The Scot was not impressed with the overall performance.
He told Sky Sports: "It was a very disruptive game, there was no flow to it.
"We started well then playing as individuals rather than groups.
"It was very frustrating, there was a lot of pushing and pulling at breakdowns.
"We could have played a lot more simply. Not taking anything away from Southland but they are probably the poorest opposition we have played. We made a lot of unforced errors and turnovers which helped them."