It's not clear whether Alastair Cook actually said those exact words; if so maybe it was a subtle commentary on England's inexplicably pitiful performances in the series so far. They certainly have been playing like a bunch of "our souls".
This is not the first time this particular fnarr-fnarr combination of words has been used for comic effect, of course, whether intentionally or not. Steve Coogan's short-lived Latino crooner creation Tony Ferrino didn't have many properly funny moments, but the epic The Valley Of Our Souls was one of them. Don't imagine it's only the low-brow end of the cultural spectrum that does this stuff, though: here's Leo Tolstoy getting a cheap laugh in a very similar way.