The 24-year-old is three weeks into the extended lay-off from contact work after consultations between Melbourne medical staff, Bail and neurosurgeon Gavin Davis found a conservative approach would give him the best chance to recover from his knocks.
Bail was forced to sit out four weeks in 2012 after failing weekly tests to satisfy club officials he was fully recovered from a head knock against Carlton in round nine.
He played 10 consecutive games after returning.
Because of that history the club has decided to take a cautious approach and, while frustrated, Bail has agreed it is the best way forward.
He is still able to carry out running drills and maintain his fitness during the six-week period.
Football manager Josh Mahoney said Bail was being continually monitored and the club was acting on the advice of one of the world's leading experts on concussions in managing his return.
"We were very conservative with him last year when he also had a period off. The positive out of that was that he was able to return to footy to play the last 10 games. We expect it to be the same this time," Mahoney said.
Bail has played 36 matches since making his debut in round 19, 2009, but looked to have established himself in the line-up last year under Mark Neeld. He has been listed as unavailable for selection for four weeks.
The club has decided to not specify a return date for injured pair Mitch Clark and Jack Trengove.
Both are progressing well in their recovery from foot injuries and remain hopeful of being in the mix for round one, but the club says their return date will become clearer as they move through the next phases of their rehabilitation.
Clark suffered a lisfranc injury in round 13 and missed the rest of the season. Trengove played every game in 2012 but a navicular fracture was found in his left foot in December. He escaped surgery but has been in rehabilitation since the injury was found.
Ruckman Max Gawn is on the long-term injury list and is six to eight weeks away from a return. Gawn, who is returning from a knee reconstruction that forced him to miss 2012, suffered a hamstring injury early in the pre-season.
The Demons are expected to play several new players in round one of the NAB Cup. The club added 14 players to its list over the off-season and will take the opportunity to play as many as possible in the two games on Friday night.
Rohan Bail is a midfielder in NAB AFL Fantasy. He averaged 61 points in 2012. Register your team at our AFL Fantasy Hub.
