“Everything’s come at once. Since Covid, it’s just every day waking up with a different thing.
“The medical team’s been brilliant. I think it’s just a victory getting on that start block there.
“Hopefully, that’ll give my body a nice little push for tomorrow.”
Peaty did not line up for Great Britain in the mixed relay final, which took place later on Saturday.
However, the Briton said he knew he would not be at 100% for the next two days as the swimming events come to a close.
“I’m glad I’ve got a heat swim [done]. It’s my first hard stuff since I had the final on Sunday last week,” he added.
“It’s been a rough week, but hopefully we’ll find a way through the next 36 hours.”
Great Britain are defending Olympic champions in the mixed event, with Peaty part of the team that won gold in Tokyo.
Richards, Tom Dean, Duncan Scott or James Guy, who won gold in the men’s 4x200m freestyle relay on Tuesday, could also come in for the final.
Britain also took silver in the men’s 4x100m medley relay in Tokyo three years ago. That final takes place on Sunday at 18:10 BST.
Earlier, Team Ireland’s Daniel Wiffen qualified fastest for Sunday’s 1500m men’s final.
Wiffen became the first athlete from Northern Ireland to win an Olympic gold medal in 36 years as he triumphed in the 800m freestyle earlier in the week.
