As part of Monday's trade, Seattle is sending Atlanta $1,788,172 to cover about one-third of the $5,677,419 remaining in Swarzak's $8 million salary this year.
Vizcaino opened the season as Atlanta's closer, then had season-ending surgery on his right shoulder on April 17. His replacement, A.J. Minter, struggled and was optioned to Triple-A Gwinnett on May 10.
The 27-year-old Biddle was designated for assignment by the Braves on Wednesday after walking 10 batters in 11 ⅔ innings. He had a 5.40 ERA as he failed to repeat his success from 2018, when he was 6-1 with a 3.11 ERA. He will report to the Mariners.
Luke Jackson has six saves in nine chances as the Braves' latest closer.
The 33-year-old Swarzak has a 5.27 ERA and three saves in six chances this season for the Mariners. He had an 8.64 ERA in his last nine appearances. Swarzak was successful in four of five save chances and had a 6.15 ERA with the Mets in 2018.