Chicago will send the Rangers $750,000 as part of Wednesday's deal to cover part of the $1.5 million remaining in the $4.65 million salary for Jones, who is on the injured list after surgery to repair a flexor mass tear in his right forearm. He is not expected to pitch again this season.
Texas also will get $1 million in international signing bonus pool allotment for 2019-20.
Jones had a 3.48 ERA in 13 relief appearances this season before going on the injured list April 27. He is 22-13 with a 3.12 ERA in 284 relief appearances in his big league career from 2012-19, all with the White Sox. His contract includes a $3.75 million club option for 2020 with a $1.25 million buyout, and also a 2021 option.
The 19-year-old Jarneski is in the Arizona League, and the 22-year-old Castro is in the Dominican Summer League.