MELBOURNE forward Dean Kent requires hamstring surgery and is facing more than two months on the sidelines.

The Demons have been delivered a double injury blow in the lead up to Sunday's game against Fremantle with lock down small defender Neville Jetta also to miss with concussion.

Kent tore his left hamstring while chasing three Richmond players during the second quarter of Friday night's 32-point victory. The speedster immediately grabbed high up in his left leg and was subbed out, leaving the game on crutches.

Roos said Kent faced a similar layoff to that of North Melbourne star Nick Dal Santo, who had hamstring surgery earlier this month.

"Kent is seeing the surgeon this afternoon and in all likelihood he'll go in for a hammy tendon op tomorrow," Roos said on Monday.

"It'll be similar to Nick (Dal Santo)– 10 weeks around that mark."

Jetta sustained a concussion late in the second term of Friday night's game against the Tigers and did not return to the field of play after half time.

Given Jetta's history with head knocks, Roos said the Demons would be careful with how the club managed the defender.

"Jetta won't play. We'll be pretty conservative. He's had three minor knocks over the last four or five weeks so we'll have to be conservative with him," Roos said.

With Kent and Jetta sidelined, the Demons will be forced to make at least two changes to the side that got the job done against Richmond.

Former skipper Jack Grimes may be recalled for Sunday's game against the Dockers, after displaying his class with 18 disposals and nine tackles for the Casey Scorpions in the VFL on Sunday.

Jimmy Toumpas (28 disposals and seven tackles) is also likely to be in the mix, while Max Gawn or Jake Spencer might get a look in as the Demons look at ways of nullifying the dominance of Dockers big man Aaron Sandilands.

Containing Fremantle's in-form midfield of Nat Fyfe, David Mundy, Michael Barlow, Stephen Hill and Lachie Neale – whom Roos described as the most underrated midfielder in the competition – will also have its challenges.

Roos said he knew when the Demons met Fremantle in their NAB Challenge battle at Fremantle Oval on March 5 that coach Ross Lyon had his team primed for a big 2015.

"It's been an impressive start. Being 4-0 is a terrific effort," Roos said.

"They're in really good nick early in the season. The end of the year will tell if they're better or worse, but I had them as a chance to win the flag this year.

"I certainly hadn't written them off like a lot of people had."