Weitering (thigh) and Williams (calf) copped knocks during the injury-hit Blues' impressive comeback win over Greater Western Sydney last week.
But Voss said the pair had done enough at training in recent days to be cleared to line up in defence against the ladder-leading Cats at the MCG on Saturday night.
"They've had a pretty reasonable week," Voss told reporters on Friday.
"I had a look at them this morning, they're ready to go ... we're pretty happy with where they're at."
Zac Williams will be back for Carlton after recovering from a calf injury. (Darren England/AAP PHOTOS)
Key defender Weitering's return to fitness is a huge boost for Carlton as they seek to shut down Geelong's star talls Tom Hawkins and Jeremy Cameron.
Cameron starred with six goals from 25 disposals last time the teams met - in round two last year - although the Blues emerged as narrow winners.
"It's somewhat of a relief having (Weitering) out there," Voss said.
"He's a very good player for us and clearly he's our vice-captain and brings something a bit different to the table.
"We're a better team with him out there and he'll play an important role.
"They've got two big guys up front that pose some problems for teams, and certainly have in the past.
"We're aware of the challenge that's in front of us."
Voss has again backed a two-pronged ruck division, with Marc Pittonet to work in partnership with Tom De Koning, who spent most of his time in attack against the Giants last week and kicked a career-high three goals.
The 24-year-old faces a battle with his younger brother and Cats key defender Sam De Koning.
Sam De Koning will line up for Geelong against his Blues brother Tom. (James Ross/AAP PHOTOS)
"You can't handle that in different ways but I certainly hope he treats it like it's another jumper," said Voss, who played against his brother Brett multiple times at AFL level.
"It's hard not to, but there's obviously an emotional buy-in there.
"I'm not sure how Tom went in the backyard against Sam - I'm not sure who won most of the dust-ups - but I'm hoping he gets the upper hand this weekend."
Geelong have recalled No.1 ruckman Rhys Stanley to face Pittonet and De Koning, while Cam Guthrie is back for his first game in 12 months after recovering from a complicated foot injury.
Zac Tuohy is also back but star defender Tom Stewart will miss out while in concussion protocols.
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