It's not the slow time in the 800m (1:50) last night that makes me think this.
Its his unwillingness to even get in the mix. Kerr made them all look like boys, sure, but I was surprised to see Centro actually looking spent after that effort. If you watched the stream, he was hanging over the fence.
Might be time for him to move up to the 5k while he's still got some speed...