The Demons, who come up against North on Saturday night, have lost their last nine matches.
“We’ve probably got eight or nine guys now that look really tired because they didn’t have pre-seasons,” Roos said after the defeat at the hands of West Coast.
“If you don’t have pre-seasons – you get a bit of a boost during the middle of the season – but once the season comes to a close, guys that have had their full pre-seasons, they’re conditioned and they’re ready to go.
“It’s really telling on those guys that look really, really tired now at the end of the season. They haven’t had the work from November through to March.”
Under Roos, Melbourne has won four games this season, two up on last year.
Without a victory against the Kangaroos since 2006, and 19 losses in a row at Etihad Stadium, the task this week doesn’t get any easier.
“There’s challenges for all of the teams around the eight that can’t make the finals – you’ve really got to dig in and find ways to improve your club in the backend of the season.”
“I’d say it’d be a pretty light week and we’ll just try and get the guys ready for one last two and a half hour crack.
“Hopefully we can regroup and put in a performance next week, but certainly our guys are pretty tired.”
Roos says the Demons will resist the temptation to bring in developing key-forward Jesse Hogan.
"We can't afford to risk him getting injured,” he added.
"He's had such a tough year. He's back training and healthy again.
“…it will be pointless playing him next week.”
