Feeling as good as he did during his prime, Smith had limited involvement at an optional training session on Sunday before Wednesday's first Test against West Indies.
The 33-year-old hit a nerve using his pso-rite, a u-shaped device designed for athletes to help loosen the psoas muscles that run from the lumbar spine to the groin.
"It was just me being just silly to be honest," Smith said. "I was hitting myself in the psoas, trying to loosen that up and I got a little low and I hit a little nerve or something. My hip is a little bit grumbly...but all will be fine."
His technical shift has been a year in the making, after believing he had got his hands right last summer before working on his feet recently.
In last month's ODIs against England, Smith was notably much stiller with his distinctive back-and-across movement gone.
The change came after Smith made a point to return his technique to where it was in 2014-15, when he averaged 128.16 against India.
In turn, it has prompted Smith to agree with a Greg Chappell column where the former captain said Smith's changes could make him better than ever.
"The reason for the changes in long-form cricket, I felt as if I was getting a bit too front-on on the back foot," Smith said. "If you're too front on you can follow the ball if it nips away from you. Or you're not getting into positions that are where I wanted to be to leave the ball as well.
"Where I've got to right now is the ultimate for me. I feel like I don't have to work as hard to access the offside with my body and my hands. I can just play with a nice flow."
But with his changes, Smith feels as if he has opened up his options on the back foot and is better placed to handle any bouncer barrage.
"I was still quite front on [when hit by Archer] and I was only being able to help [pull shots] on their way behind square," Smith said. "Whereas using power in front of square is something I've probably done a bit better throughout my career.