PAUL Medhurst, Josh Fraser and John Anthony are among the big names who will miss Collingwood's intensive training block at its altitude camp in Arizona.

On Monday, about 20 Magpies - along with coaching and fitness staff - departed Melbourne for the training base in Flagstaff, which the club has visited during three previous pre-season campaigns.

Head of conditioning David Buttifant said a group of players would remain training in Melbourne until their teammates returned on December 9.

"We've probably got about 12 that are staying behind," Buttifant said.

"It may be for technical reasons, purely to work on skills or it may be rehab from surgery … some guys we think are better off staying here to work on other areas.

"We've got coaches staying back and conditioning staff to look after them … and they'll continue training and doing their work back here."

Fraser continues to recover from the knee injury he battled late in the 2009 season, Medhurst is managing the workload on his ankle while Anthony had post-season surgery on a shoulder but has been training.

Several youngsters will also stay behind and will be joined by the Pies' new recruits following Thursday's NAB AFL Draft.

The travelling party will meet up with captain Nick Maxwell, vice-captain Scott Pendlebury and Dale Thomas, who were part of an eight-man squad to hit the US a week early.

They endured some high-altitude training in Colorado before travelling to Flagstaff.

Buttifant said the Pies had been using their altitude room at the Lexus Centre in recent weeks in a bid to acclimatise players ahead of the trip.

He said that the players were comfortable with their program and wouldn't be altering it from previous visits.

"We've got a really good template there as far as what to do and how to go about it," Buttifant said.

"We do a lot of footy-specific stuff, and we throw a few hikes in as well, but ultimately it's about football training and that's what we do.

"We train at high [altitude] conditions and do a lot of weight training as well. It’s a very intensive training block where they're training at altitude two to three times a day and just get a breather at night time, so it’s full on."