Marlins Roster & Staff
Marlins
| Date | Transaction |
| 06/21/21 | Miami Marlins sent 3B Deven Marrero outright to Jacksonville Jumbo Shrimp. |
| 06/19/21 | Miami Marlins selected the contract of SS Luis Marte from Jacksonville Jumbo Shrimp. |
| 06/19/21 | Miami Marlins designated 3B Deven Marrero for assignment. |
| 06/18/21 | Miami Marlins optioned SS Isan Diaz to Jacksonville Jumbo Shrimp. |
| 06/18/21 | Miami Marlins optioned CF Lewis Brinson to Jacksonville Jumbo Shrimp. |
| 06/18/21 | Miami Marlins activated RHP Cody Poteet from the 10-day injured list. |
| 06/18/21 | Miami Marlins sent RHP Luis Madero outright to Jacksonville Jumbo Shrimp. |
| 06/18/21 | Miami Marlins activated SS Miguel Rojas. |
| 06/16/21 | Miami Marlins designated RHP Luis Madero for assignment. |
| 06/16/21 | Miami Marlins selected the contract of 3B Deven Marrero from Jacksonville Jumbo Shrimp. |
| 06/15/21 | Miami Marlins placed LF Corey Dickerson on the 10-day injured list. Left foot contusion. |
| 06/15/21 | Miami Marlins recalled CF Jesus Sanchez from Jacksonville Jumbo Shrimp. |
| 06/15/21 | Miami Marlins optioned LHP Braxton Garrett to Jacksonville Jumbo Shrimp. |
| 06/15/21 | Miami Marlins recalled CF Lewis Brinson from Jacksonville Jumbo Shrimp. |
| 06/15/21 | Miami Marlins sent RHP Preston Guilmet outright to Jacksonville Jumbo Shrimp. |
| 06/14/21 | Miami Marlins placed SS Jose Devers on the 10-day injured list. Right shoulder impingement. |
| 06/14/21 | Miami Marlins placed 3B Brian Anderson on the 60-day injured list. Left shoulder subluxation. |
| 06/14/21 | Miami Marlins selected the contract of RHP Luis Madero from Jacksonville Jumbo Shrimp. |
| 06/13/21 | Miami Marlins activated LHP Trevor Rogers from the 10-day injured list. |
| 06/13/21 | Miami Marlins signed free agent RHP Robinson Martinez to a minor league contract. |
| 06/13/21 | Miami Marlins sent SS Miguel Rojas on a rehab assignment to Jacksonville Jumbo Shrimp. |
| 06/13/21 | Miami Marlins designated RHP Preston Guilmet for assignment. |
| 06/13/21 | Houston Astros traded C Lorenzo Quintana to Miami Marlins. |
| 06/12/21 | Miami Marlins selected the contract of RHP Preston Guilmet from Jacksonville Jumbo Shrimp. |
| 06/12/21 | Miami Marlins placed LHP Trevor Rogers on the 10-day injured list. |
| 06/12/21 | Miami Marlins signed free agent LF Zack Zehner to a minor league contract. |
| 06/11/21 | Miami Marlins signed free agent LHP Mason Melotakis to a minor league contract. |
| 06/10/21 | Miami Marlins signed free agent RHP Oscar Araba to a minor league contract. |
| 06/09/21 | Miami Marlins signed free agent LHP Eric Stout to a minor league contract. |
| 06/09/21 | Miami Marlins placed 1B Garrett Cooper on the 10-day injured list. Lumbar strain. |
| 06/09/21 | Miami Marlins recalled 1B Lewin Diaz from Jacksonville Jumbo Shrimp. |
| 06/08/21 | Miami Marlins recalled LHP Braxton Garrett from Jacksonville Jumbo Shrimp. |
| 06/08/21 | Miami Marlins placed LHP Daniel Castano on the 10-day injured list. Left shoulder impingement. |
| 06/07/21 | Miami Marlins optioned CF Lewis Brinson to Jacksonville Jumbo Shrimp. |
| 06/07/21 | Miami Marlins recalled LHP Daniel Castano from Jacksonville Jumbo Shrimp. |
| 06/06/21 | Miami Marlins sent SS Luis Marte outright to Jacksonville Jumbo Shrimp. |
| 06/05/21 | Miami Marlins placed RHP Elieser Hernandez on the 60-day injured list. Right quad strain. |
| 06/05/21 | Miami Marlins selected the contract of RHP Zach Thompson from Jacksonville Jumbo Shrimp. |
| 06/05/21 | Miami Marlins sent RHP Jordan Holloway on a rehab assignment to Jacksonville Jumbo Shrimp. |
| 06/05/21 | Miami Marlins placed RHP Cody Poteet on the 10-day injured list. Sprained right MCL. |
| 06/04/21 | Miami Marlins recalled CF Lewis Brinson from Jacksonville Jumbo Shrimp. |
| 06/04/21 | Miami Marlins placed RHP Elieser Hernandez on the 10-day injured list. Right quad strain. |
| 06/03/21 | Miami Marlins traded RHP Tyler Jones to Arizona Diamondbacks. |
| 06/03/21 | Miami Marlins designated SS Luis Marte for assignment. |
| 06/03/21 | Miami Marlins activated RHP Elieser Hernandez from the 60-day injured list. |
| 06/03/21 | Miami Marlins optioned CF Lewis Brinson to Jacksonville Jumbo Shrimp. |
| 06/01/21 | Miami Marlins signed free agent SS Galli Cribbs Jr. to a minor league contract. |
| 06/01/21 | Miami Marlins signed free agent SS Justin Twine to a minor league contract. |
| 06/01/21 | RHP Andrew Bellatti assigned to Miami Marlins. |
