The Tigers have been successful in signing up a number of key young players in recent weeks, but Riewoldt and Martin remain out of contract beyond this season, with money reported to be a sticking point.
Cotchin, who committed to the club for a further two years in May, said players needed to be prepared to make financial sacrifices to be part of successful teams.
He said "everything going forward is fair and reasonable", and he couldn't see any reason why the duo wouldn't want to stay with the Tigers.
"It's a great place to be, we've got a young group that have been together now for quite some time and we're building towards something," Cotchin said on Tuesday.
"Every player in the AFL would love to be paid as much as they possibly can, but the reality is there's a cap there for that reason. If you want to be part of successful clubs, then sometimes there's a little bit of sacrifice that needs to be made.
"We're all about spending time together, building something and enjoying the whole ride together."
Cotchin plays his 100th game this Saturday against Gold Coast in Cairns, and the midfielder said he was hoping for an improved performance from the Tigers as they look to beat the Suns for the first time.
The 23-year-old said the players had learned lessons from their 62-point loss to North Melbourne last Saturday, adding this week's review had been forensic.
"When you have a disappointing result go your way the week prior, you always want to come out and prove that you're still playing good footy," he said.
"We've let ourselves down the last couple of years (in Cairns), but we're a different team the way we've been playing in the last few weeks. Aside from last week, we've really come a long way.
"The conditions up in Cairns are a little bit different to down in Melbourne and we're prepared for that … we've had two years of it now, we know what to expect."
On his own form, Cotchin said he'd "love to get a lot more of the ball and kick a few more goals", with his output in both areas down on 2012, when he finished equal runner-up in the Brownlow Medal.
The All Australian denied he was carrying a knee injury from earlier in the season, and said he was spending less time forward of centre.
"That (goal kicking) is probably down in comparison to last year and I'm not giving myself as much opportunity," he said.
"I think it's just a matter of some of our younger guys really stepping up to the plate.
"Brandon Ellis, Reece Conca, even (Nick) Vlastuin has come in and played a really pivotal role for our footy club.
"That's what we ask of our younger guys, to start to take up the slack that's been there for the past couple of seasons."
Nathan Schmook is a reporter for AFL Media. Follow him on Twitter @AFL_Nathan
