To replace Cishek on the roster, the Marlins recalled right-hander Andre Rienzo from Triple-A New Orleans.
Moving Cishek was expected, but still was an emotional decision, considering his reputation within Miami's organization.
"Mixed emotions," manager Dan Jennings said. "We called Shrek [Cishek] on the phone. It was a very heartfelt conversation. You know it's the business of baseball. At the same time, when you have a guy that you see grow through your system. This is the character of who Steve Cishek is. The wonderful person he is. The way he respected his teammates and his teammates respected him."
The Cards will pick up the remainder of Cishek's $6.65 million salary. He will be a free agent after the 2016 season.
Trading Cishek is the first of what could be close to a handful of deals by the Marlins before the July 31 Trade Deadline. Mat Latos, Dan Haren and Michael Morse are other potential trade candidates.
Talks intensified in the past day regarding Cishek, who also drew interest from the Dodgers, Pirates and Twins.
Cishek, who made his Major League debut in 2010, appeared in 284 games, converting 94 of 108 save chances. He took over as closer midway through the 2012 season and held the job until he stumbled and was replaced in mid-May of this year by A.J. Ramos.
Only Robb Nen (108) and Antonio Alfonseca (102) have more saves as a Marlin than Cishek.
Cishek's departure means Miami will look more at lefty Brad Hand, primarily a long reliever, in a setup role.
Cishek made his final Miami appearance in Thursday's 4-0 win over the Padres at Petco Park. He worked a clean eighth inning.
For the season, Cishek is 2-6 with a 4.50 ERA, striking out 28 in 32 innings. He has not allowed a run in seven innings over his past seven outings.
Barraclough, 25, had a 2-0 record with a 3.28 ERA and eight saves in nine chances for Double-A Springfield. He opened the season at Class A Advanced Palm Beach, throwing 15 innings there before the promotion to Double-A.
The right-hander, a seventh-round Draft pick in 2012, throws 98 mph and will be assigned to Double-A Jacksonville.
"A couple of our scouts identified him as what could be a quick climber," Miami assistant general manager Mike Berger said. "I don't want to put that on Kyle right now. Let's get him into the system, let that power stuff play."