Finch is the latest high-profile figure to withdraw from the competition which has been beset by changes to the eight squads due to the demands of the schedule, injuries and fatigue.
Jordan Thompson, the Yorkshire all-rounder, has also been drafted in by Superchargers as a replacement for Olly Stone, the injured England fast bowler.
Thompson is one of seven Yorkshire players in the squad based at Emerald Headingley along with Adil Rashid, David Willey, Adam Lyth, Harry Brook, Tom Kohler-Cadmore and Matthew Fisher, while county team-mates Joe Root and Dawid Malan are playing for Trent Rockets, Jonny Bairstow for Welsh Fire and Lockie Ferguson for Manchester Originals.
Superchargers have also brought in Durham all-rounder Ben Raine as their “wild-card” pick, with each franchise able to add one player to finalise their squad.
The women’s squads have been similarly impacted, with Superchargers women announcing four changes.
South Africa’s Laura Wolvaardt and Australia’s Laura Kimmince have been signed to replace Australia’s Alyssa Healy and Nicola Carey, while Sterre Kalis and Kalea Moore complete their domestic roster after impressing for Northern Diamonds and South East Stars.
Commenting on his appointment as Superchargers’ men’s captain, du Plessis, 36, who has scored over 11,000 runs for South Africa across the formats, said: “I’m extremely excited. It’s really pleasing to be part of what will be a pioneering tournament, something new.
“I’ve looked at the names in our squad and I’m really excited to play with some of the guys that I’ve played IPL with and played a lot of international cricket against.
“There’s a lot of international talent in there and some really good up-and-coming talent, so I’m delighted to be joining them.”
Wolvaardt, a 22-year-old batter who has played 88 white-ball games for South Africa, is a huge du Plessis fan and delighted to have joined Superchargers’ women.
With the men’s and women’s teams intertwining in the shape of double-headers, she is excited by the chance to pick his brains.
“It’s going to be awesome,” she said. “I’m a bit of a Faf fangirl. He’s such a legend in South Africa and to be able to play (double-header) games prior to him will be great. Hopefully I’ll be able to speak to him a bit, hear what ideas he has about the game and the new format as well.”
The men’s Hundred runs from July 22 to August 21, with the women’s event starting a day earlier. The men’s competition clashes with the 50-over One-Day Cup, which runs from July 22 to August 19.