CARLTON has suffered a significant blow with emerging defender Caleb Marchbank set to miss the next four weeks with an ankle injury. 

Marchbank came from the ground midway through the first term of the Blues' 24-point loss to Collingwood last Friday night, returning to play some of the second quarter before sitting out the entire second half.  

Carlton football manager Andrew McKay told the club's website Marchbank's rehabilitation would be managed conservatively.  

"He obviously didn't play the whole game and went off injured with that ankle. There's not a whole lot of damage there thankfully but he will be out for around four weeks," McKay said.  

"[His return date] will depend on his level of pain tolerance when he makes his way back into the skills program."  

Marchbank will be sorely missed by Carlton when it takes on North Melbourne at Blundstone Arena on Saturday night given the Roos' attack boasts twin towers Ben Brown and Jarrad Waite.  

Meanwhile, the Blues will also be unable to call on ex-Port Adelaide ruckman Matthew Lobbe for about four weeks after he suffered a quad injury in the Northern Blues' round one loss to Collingwood's VFL team on Saturday.  

However, former Cats midfielder Darcy Lang could return from an ankle injury in the VFL this weekend but will have to pass a fitness test.  

McKay also said Ciaran Byrne (quad) and Tom Williamson (back) were both expected to return in about three weeks, while Alex Silvagni (hamstring) should resume full training in two to three weeks.