Walters on Wednesday said Capewell's neck stiffness that will see him miss Thursday's clash with the Rabbitohs was caused when he was drying himself with a towel at home.
The back-rower was in serious pain earlier this week but, in a positive sign he'll be fit for next week's Magic Round clash with Manly, was moving freely on Wednesday.
"He hurt it drying himself with a towel," Walters told media while doing his best to re-enact the movement.
His absence along with form prop Payne Haas (shoulder) will be tough to handle as the sides, both 4-4 this season, fight to stay in the top eight.
Brisbane have leaked just four points in total in their past two second halves and kept a rattled Souths to just four points in their round-one win.
"Kurt's a big part of our defence, but I've been particularly impressed with our right-side defence with Kotoni (Staggs) and Selwyn (Cobbo) and that's where Souths like to run," Walters said.
"So we need to be strong there and make sure Jordan Riki and Reyno do a good job (on the left side without Capewell)."
Reynolds had COVID-19 and missed Brisbane's season-opening upset defeat of his former club, but has been instrumental in the Broncos' form rebound in the last fortnight.
The Rabbitohs are short-priced favourites to square this season's ledger in Sydney but the halfback could inspire his new side again.
"His influence over our team has been great and he's got some knowledge on Souths," Walters said.
"It's his first game against his old club; we want to make sure it's a good performance from all our guys to support him.
"It's a special week for him."
If Reynolds doesn't inspire the Rabbitohs, maybe it will be club patriarch George Piggins who does.
The ailing Piggins was a surprised visitor to Souths' captain's run on Wednesday and his presence didn't go unnoticed at Redfern.
"Obviously he's a legendary player and coach here and then played a huge part in the club's reinstatement and surviving and staying in the game," said coach Jason Demetriou.
"He is South Sydney and we haven't seen him a lot - or I haven't while I've been down here - so it was great to see a couple of players go over to the stands and sit with him and be respectful.
"It just gives them a sense of perspective about what the club's about."
The Rabbitohs will roll out the same starting side that beat Manly last week, although Tom Burgess will be a match-day decision for Demetrious after sitting out training with back spasms.
TC Robati will start alongside the returning Pat Carrigan (knee) as Brisbane hunt a third straight win for the first time since 2019.
