Imran Tahir, Mohammad Hasnain, David Wiese and Ben McDermott are among the players added to the eight squads as an additional foreign player
Eight overseas wildcard picks have been confirmed ahead of the second edition of the men's Hundred.
Imran Tahir has returned to Birmingham Phoenix after being originally released and then not selected in the player draft.
The 43-year-old lit up last year's tournament with the first hat-trick in the competition's history against Welsh Fire.
Finn Allen, who played for Phoenix last season, has been picked up by defending champions Southern Brave.
Pakistan youngster Mohammad Hasnain was the No.1 pick by Oval Invincibles.
The 22-year-old had been banned from bowling since February but following a reassessment of his action is now available to bowl again.
"I'm overjoyed to be joining Oval Invincibles," he said. "The Hundred looked like great fun last year and I can’t wait to get involved.
Finn Allen has swapped Birmingham Phoenix for Southern Brave (Harry Trump/Getty Images)
"The opportunity to play alongside stars like Sunil Narine, Jason Roy and the Curran brothers is hugely exciting. I’m really looking forward to getting back out on the field again."
David Wiese has been picked up by Northern Superchargers after being contracted at London Spirit while Hampshire's Ben McDermott comes through the door at the Lord's-based franchise.
Durham's Ashton Turner has been signed up by Manchester Originals and Noor Ahmad, the Afghanistan left-arm spinner, is a new face at Welsh Fire.
The new additions, who will be paid £50,000 each, are completed by Daniel Sams, currently with Essex for the T20 Blast, joining Trent Rockets.
While teams will only be eligible to field three overseas players in an XI, the addition of a fourth player is to ensure minimal disruption from withdrawals.
Those overlooked include Qais Ahmad, Shimron Hetmyer, Marnus Labuschagne and Evin Lewis, while Dewald Brevis, Tristan Stubbs and Jimmy Neesham were added to the long list of players since the draft but also missed out.
There remains one vacant berth in each of the eight squads that will be filled by a domestic wildcard player, which is expected to be confirmed in July.
Ben McDermott (Warren Little/Getty Images)
The men's tournament kicks off on August 3 with Southern Brave taking on Welsh Fire at The Ageas Bowl.
Men's Hundred wildcards
Oval Invincibles: Mohammad Hasnain
Northern Superchargers: David Wiese
London Spirit: Ben McDermott
Manchester Originals: Ashton Turner
Welsh Fire: Noor Ahmad
Birmingham Phoenix: Imran Tahir
Trent Rockets: Daniel Sams
Southern Brave: Finn Allen