Johnson cited Barkley's weak defence as the reason for the omission, preferring instead to choose Wasps pair Dominic Waldouck and Riki Flutey in addition to the summer pairing of Shontayne Hape and Mike Tindall.
But McGeechan believes the 28-year-old's his current form is as good as any in the Aviva Premiership.
"Olly's started the season very well and he's trained very well," said McGeechan. "Martin's now spoken to Steve Meehan and myself and we know what we're trying to do.
"We'll do everything we can to get Olly in the strongest position, but selection is still subjective and it always will be.
"They've got their view of the type of player they want and they've spoken to Olly. That's fine, that's confidential between them.
"So if we know that we can relate the right things back to him and if Olly's doing that and playing well then he's always in the frame. He has to be considered.
"My view as a club coach is that I want to make it the best environment it can be to put my players in international rugby.
"Having met with Martin and Rob Andrew last week, I think they're going around all the clubs talking and just giving an idea of what they want and what they're looking for.
"It's only two games into the season, but he's trained well and I've been impressed with him and that's all he can keep on doing."