Somerset quick Baker replaces injury victim Tymal Mills, while South Africa left-armer Hendricks comes in for Craig Overton for at least two matches
Defending men's Hundred champions Southern Brave have been forced into more additions to their squad to cover for injury and international selection.
Somerset seamer Sonny Baker has been added to the group after Tymal Mills was ruled out of the tournament with a cut toe.
And South Africa and Leicestershire left-arm seamer Beuran Hendricks arrives for at least two matches as cover for Craig Overton, who is with the England squad for the first South Africa Test at Lord's.
Hendricks' spell covers the matches against Manchester Originals (August 18) and Welsh Fire (August 22) but could yet be extended.
The call-ups see both players leave their respective counties' Royal London Cup campaigns.

Chris Jordan's replacement has yet to be confirmed (Dan Mullan/Getty Images)
Overton, who has only played one men's Hundred match, was named as part of the squad for the first two Tests of the series. The second Test at Old Trafford runs between August 25-29.
A stand-in for Chris Jordan will be announced in due course after his tournament was ended by injury earlier this week.
After romping to the title in the first season of the 100-ball tournament, Brave have struggled in season two, limping to just a single win from their four matches.
Having started without Quinton de Kock due to his international commitments, The Ageas Bowl-based franchise have recently lost Marcus Stoinis due to his involvement in Australia's one-day international series against Zimbabwe.