DEFENDER Neville Jetta has joined a growing list of Melbourne players ruled out for the rest of the season as he prepares for further surgery on his troublesome knee.

Sidelined for 11 matches mid-season before returning for the past three, Jetta is one of four changes for Saturday night's clash against Richmond at the MCG.

He joins a casualty list that includes Sam Weideman, Kade Kolodjashnij, Jeff Garlett and Tom McDonald after a Demons' season from hell. 

"He's obviously come back after a long knee rehab and he's still getting some continual swelling in that knee, so we'll go in and get that tidied up," coach Simon Goodwin said.

"It's something that's been an issue for him the whole year, so we just want to make sure he's 100 per cent right to go and we feel it's a bit unfair putting him out there with a swollen knee."

The Demons' eighth loss in 10 matches to St Kilda last week was riddled with kicking errors prompting Goodwin to flag some new tricks in attack this week.

"Our method in our offence needs to improve which is part system but also our execution and we're well aware of that as a group," he said.

"We think we're going to implement a few things on the weekend that we think will challenge that and hopefully make it better it, refine it.

"That's one of our challenges, is not to waste time, not to waste the next four weeks."

Jake Lever, Sam Frost and Oscar McDonald will be left to handle Richmond spearheads Jack Riewoldt and Tom Lynch with high-priced recruit Steven May ruled out for a second match.

Goodwin insisted May, who ran strongly with the rehab group on Friday, would be fit to return from his hamstring to tackle Collingwood next week.

Jake Melksham returns against the Tigers for his first game since round eight, recalled alongside Kyle Dunkley, Braydon Preuss and Jay Kennedy Harris.

Preuss earns a reprieve to add firepower in attack after the Demons lost Tim Smith (toe). Alex Neal-Bullen and Josh Wagner have been dumped.

Meantime, co-captain Nathan Jones is closing in on a contract extension after a prolonged negotiation period.

"The club have put something to Nathan a fair while ago, Nathan's a highly valued person at the Melbourne footy club, he has been, he always will be," Goodwin said.

"I'm really confident Nathan's going to be a one club player and that'll get sorted out very shortly and it's something that will move forward pretty quickly."