NORTH Melbourne's long list of big men on modified training duties has been cut by one, with defender Nathan Grima completing a conditioning session for the first time on Tuesday.



The Roos had been holding Grima back this pre-season, wary of overloading his repaired navicular bone.



But the 29-year-old has been given the all clear by club medicos to start building his workload.



"I had another block of time off and today was probably the first decent running block I’ve done since the last game," he told North Melbourne's website.



"It was pretty hard work but it’s nice to get through it.



"It was always (the plan), once that last game finished, (to) give it another extended time just to be safe.”



Grima's history of injury problems continued to haunt him in 2014, with the 192cm backman struggling through pre-season due to a back issue before his navicular pain flared after round seven.



With his contract set to expire, Grima fought his way back into the side before finals and his hard work was justified when he played in North's rollercoaster September campaign and signed a one-year contract extension.



"It looked like I might’ve even missed the whole year at some stage and the situation I was in, with my age and my contract, I’d do anything to get back and play," Grima said.



"To play in three finals was awesome and obviously we didn’t finish the way we’d like to, but to get into a preliminary final was amazing and it set the tone for this pre-season.”



While Grima – who has played 86 games in seven injury-interrupted seasons at Arden Street - is ramping up his training workload, many of North's other big men remain on modified programs.

Drew Petrie (ankle), Ben Brown (knee), Robbie Tarrant (leg) and Majak Daw (foot) are all still building their fitness following surgery last year.