Marlins Roster & Staff
Transactions
| Date | Transaction |
| 05/30/21 | Miami Marlins sent LHP Shawn Morimando outright to Jacksonville Jumbo Shrimp. |
| 05/29/21 | Miami Marlins sent CF Lewis Brinson on a rehab assignment to Jacksonville Jumbo Shrimp. |
| 05/28/21 | Miami Marlins selected the contract of SS Luis Marte from Jacksonville Jumbo Shrimp. |
| 05/28/21 | Miami Marlins placed SS Miguel Rojas on the 10-day injured list. Left index finger dislocation. |
| 05/28/21 | Miami Marlins activated LF Starling Marte. |
| 05/28/21 | Miami Marlins optioned 1B Lewin Diaz to Jacksonville Jumbo Shrimp. |
| 05/27/21 | C Jhon Nunez assigned to Miami Marlins. |
| 05/27/21 | Miami Marlins recalled 1B Lewin Diaz from Jacksonville Jumbo Shrimp. |
| 05/27/21 | Miami Marlins placed RHP Nick Neidert on the 10-day injured list. Right biceps inflammation. |
| 05/26/21 | Miami Marlins recalled RHP Nick Neidert from Jacksonville Jumbo Shrimp. |
| 05/26/21 | Miami Marlins designated LHP Shawn Morimando for assignment. |
| 05/25/21 | Miami Marlins placed 3B Brian Anderson on the 10-day injured list. Left shoulder subluxation. |
| 05/25/21 | Miami Marlins activated SS Isan Diaz from the 7-day injured list. |
| 05/24/21 | Miami Marlins activated C Jorge Alfaro. |
| 05/24/21 | Miami Marlins optioned C Chad Wallach to Jacksonville Jumbo Shrimp. |
| 05/24/21 | Miami Marlins sent LF Starling Marte on a rehab assignment to Jacksonville Jumbo Shrimp. |
| 05/23/21 | Miami Marlins recalled SS Jose Devers from Jacksonville Jumbo Shrimp. |
| 05/23/21 | Miami Marlins placed SS Isan Diaz on the 7-day injured list. |
| 05/22/21 | Miami Marlins selected the contract of LHP Shawn Morimando from Jacksonville Jumbo Shrimp. |
| 05/22/21 | Miami Marlins placed RHP Jordan Holloway on the 10-day injured list. Right groin strain. |
| 05/22/21 | Miami Marlins placed RHP Elieser Hernandez on the 60-day injured list. Right biceps inflammation. |
| 05/21/21 | Miami Marlins signed free agent SS Zack Kone to a minor league contract. |
| 05/19/21 | Miami Marlins signed free agent SS Yelinson Pena to a minor league contract. |
| 05/18/21 | Miami Marlins sent RHP Elieser Hernandez on a rehab assignment to Jacksonville Jumbo Shrimp. |
| 05/18/21 | Miami Marlins placed CF Lewis Brinson on the 10-day injured list. Left middle finger sprain. |
| 05/18/21 | Miami Marlins recalled RHP Cody Poteet from Jacksonville Jumbo Shrimp. |
| 05/16/21 | Miami Marlins activated SS Jazz Chisholm Jr. |
| 05/16/21 | Miami Marlins optioned LHP Braxton Garrett to Jacksonville Jumbo Shrimp. |
| 05/16/21 | Miami Marlins sent RHP Luis Madero outright to Jacksonville Jumbo Shrimp. |
| 05/15/21 | Miami Marlins recalled LHP Braxton Garrett from Jacksonville Jumbo Shrimp. |
| 05/15/21 | Miami Marlins optioned RHP Cody Poteet to Jacksonville Jumbo Shrimp. |
| 05/13/21 | Miami Marlins signed free agent 2B Carlos Arroyo to a minor league contract. |
| 05/12/21 | Miami Marlins designated RHP Luis Madero for assignment. |
| 05/12/21 | Miami Marlins selected the contract of RHP Cody Poteet from Jacksonville Jumbo Shrimp. |
| 05/11/21 | Miami Marlins sent SS Jazz Chisholm Jr. on a rehab assignment to Jacksonville Jumbo Shrimp. |
| 05/11/21 | Miami Marlins sent C Jorge Alfaro on a rehab assignment to Jacksonville Jumbo Shrimp. |
| 05/09/21 | Miami Marlins selected the contract of RHP Luis Madero from Jacksonville Jumbo Shrimp. |
| 05/09/21 | Miami Marlins placed RHP Jorge Guzman on the 60-day injured list. Right elbow spur. |
| 05/09/21 | Miami Marlins optioned LHP Daniel Castano to Jacksonville Jumbo Shrimp. |
| 05/08/21 | Miami Marlins optioned SS Jose Devers to Jacksonville Jumbo Shrimp. |
| 05/08/21 | Miami Marlins signed free agent 3B Deven Marrero to a minor league contract. |
| 05/08/21 | Miami Marlins signed free agent 2B Nick Lovullo to a minor league contract. |
| 05/08/21 | Miami Marlins recalled LHP Daniel Castano from Jacksonville Jumbo Shrimp. |
| 05/04/21 | Miami Marlins optioned CF Monte Harrison to Jacksonville Jumbo Shrimp. |
| 05/04/21 | Miami Marlins activated 3B Brian Anderson from the 10-day injured list. |
| 05/04/21 | Miami Marlins selected the contract of LHP Rob Zastryzny from Long Island Ducks. |
| 05/04/21 | Miami Marlins selected the contract of RHP Anthony Bender from Marlins Alternate Training Site. |
| 05/03/21 | Miami Marlins signed free agent SS Ricky Aracena to a minor league contract. |
| 05/03/21 | RHP Paul Campbell roster status changed by Miami Marlins. |