Sheffield Steelers star is "gutted" after moneyspinning move falls through.
A change in management at Astana has meant a change of direction - and the club has en decided against employing the Great Britain defenceman.
Sheffield coach Paul Thompson said: "If he doesn't end up going anywhere then he'd be a useful addition to our roster again, as I haven't replaced his position yet.
"But it's up to Ben what his next move will be."
O'Connor pronounced himself "gutted" by the U-turn.
He tweeted: "Well that didn't last long. Gutted doesn't come close!! Shortest contract in KHL history?"
Meanwhile two new imports have agreed terms with Sheffield.
A forward and defenceman will be unveiled when all formalities have been completed.
Both are thought to be new to the Elite League.
Thompson said: "Yes, we have made headway with a couple of new guys and they will be announced shortly.
"We are after a younger group while also taking account that experience will be useful in a league like ours.
"The market is a little slow for everybody right now, not just us.
"But a lot of work is going on behind the scenes and we are confident we can put together the type of group that we want."
Sheffield, who have experience in the likes of Jonathan Phillips, Mathieu Roy and Mark Matheson, recently inked the signature of 26-year-old Josh Pitt, a Canadian forward, their only new full-import player so far.