The Magpies, who have won five matches in a row to sit fourth on the ladder, should regain Leon Davis – a late withdrawal against Fremantle on Saturday through illness – while Scott Pendlebury (knee) is an outside chance to return.
Pendlebury has missed just one game since twisting his knee awkwardly against the Sydney Swans and straining a medial ligament.
“Scott was jogging on it at the weekend,” O’Bree said on Monday morning.
“He’ll train all this week and give himself every chance to play, but we’ll only have one main training session tomorrow [Tuesday]. It’ll depend on how he gets through that tomorrow.”
O’Bree said Davis should recover from the “common cold” he was suffering last week to play in front of an expected 80,000-plus fans at the MCG on Friday night.
The Magpies will be eager to redeem themselves from their Anzac Day defeat to the Bombers back in round five, when Matthew Knights’ side stormed home with three goals in the dying minutes.
O’Bree says his side has moved on from the “one that got away” as it tries to make it six victories on the trot.
“We sort of let ourselves down [that day],” O’Bree said.
“We were in a winning position, and to their credit, the way they fought [back] in the last five minutes and won the game, that was a great effort by them.
“So we can’t really dwell on that - that’s gone now, we’ve let that slip. We’ve got another game, and we don’t want to let ourselves down this week.”
The Bombers are likely to be without in-form midfielder Jobe Watson (ankle) after the 24-year-old was injured in last Friday's superb win over Carlton, with O'Bree admitting Watson's absence would help the Magpies.
The Pies watched Friday's game closely and paid particularly attention to the new wave of Essendon youngsters on the rise, many of whom did the damage in round five.
“They’re in good form; they’ve got a lot of young guys that are really stepping up and playing some good footy, so we’re aware of that,” he said.
