AS SPECULATION continues about how Melbourne’s ruck division will play out in the absence of Mark Jamar with a foot injury, coach Dean Bailey has made it clear that only two positions are up for grabs.

Bailey said it was unlikely Paul Johnson, John Meesen and Jake Spencer will all feature in the same team this season.

He said Johnson and one of Meesen or Spencer will take on North Melbourne, but squeezing the three big men in the 22 was not in Melbourne's plans. 

Although Johnson has proven to be a handy forward option, Bailey said he was expecting the versatile tall to step-up in 2009.

"Paul has shown he can certainly play forward. He's very mobile. We used him as that second ruckman who can come in," Bailey said from the Junction Oval, where the Demons were training on Monday.

"Paul's a player who's got potential and he really needs to start to deliver. He's been in the game long enough and he needs to turn potential into consistent reality. So there is pressure on Paul to perform well."

Bailey also spoke up for Meesen, who has yet to play a match for the Demons, despite crossing to the club at the end of the 2007 season. He played two matches for Adelaide after being chosen at No.8 in the 2004 NAB AFL Draft.

"Meesen is only 22, because he's been around for so long, some people refer to him like he's a 10-year player," he said.

"Young Spencer has improved over the NAB Cup and we've elevated him [from the rookie list] to see how he goes and if he gets a chance, great.”

Bailey said defender Jared Rivers is also in the mix to play his first match since round 11 last year, after hip and groin injuries ruined his 2008.

"If the medical team give him the all clear and he can get through training, I think Jared will be in that [squad of] 28 [players for round one]," he said.