Mets Roster & Staff
Transactions
| Date | Transaction |
| 07/31/21 | New York Mets signed RHP Calvin Ziegler. |
| 07/31/21 | New York Mets activated SS Javier Baez. |
| 07/31/21 | New York Mets sent RHP Akeem Bostick outright to Syracuse Mets. |
| 07/31/21 | New York Mets designated LHP Anthony Banda for assignment. |
| 07/31/21 | New York Mets optioned RHP Trevor Williams to Syracuse Mets. |
| 07/30/21 | New York Mets activated RHP Carlos Carrasco. |
| 07/30/21 | New York Mets sent RHP Roel Ramirez outright to Syracuse Mets. |
| 07/30/21 | New York Mets placed RHP Sean Reid-Foley on the 60-day injured list. Right elbow inflammation. |
| 07/30/21 | New York Mets optioned RHP Akeem Bostick to Syracuse Mets. |
| 07/30/21 | Chicago Cubs traded SS Javier Baez, RHP Trevor Williams and cash to New York Mets for OF Pete Crow-Armstrong. |
| 07/30/21 | Chicago Cubs traded SS Javier Baez, RHP Trevor Williams and cash to New York Mets for OF Pete Crow-Armstrong. |
| 07/30/21 | New York Mets activated RHP Carlos Carrasco. |
| 07/30/21 | Chicago Cubs traded SS Javier Baez, RHP Trevor Williams and cash to New York Mets for OF Pete Crow-Armstrong. |
| 07/30/21 | New York Mets designated RHP Akeem Bostick for assignment. |
| 07/30/21 | New York Mets designated RHP Nick Tropeano for assignment. |
| 07/30/21 | New York Mets activated RHP Carlos Carrasco. |
| 07/30/21 | New York Mets sent RHP Jerad Eickhoff outright to Syracuse Mets. |
| 07/28/21 | New York Mets signed RHP Dominic Hamel. |
| 07/28/21 | New York Mets designated RHP Jerad Eickhoff for assignment. |
| 07/28/21 | New York Mets signed free agent C Tommy Gomez to a minor league contract. |
| 07/28/21 | New York Mets selected the contract of RHP Akeem Bostick from Syracuse Mets. |
| 07/27/21 | New York Mets selected the contract of RHP Jerad Eickhoff from Syracuse Mets. |
| 07/27/21 | New York Mets optioned 3B Travis Blankenhorn to Syracuse Mets. |
| 07/27/21 | New York Mets designated RHP Roel Ramirez for assignment. |
| 07/27/21 | New York Mets optioned RHP Nick Tropeano to Syracuse Mets. |
| 07/26/21 | New York Mets recalled RHP Nick Tropeano from Syracuse Mets. |
| 07/25/21 | New York Mets signed free agent RHP Jerad Eickhoff to a minor league contract. |
| 07/24/21 | New York Mets signed OF Matt Rudick. |
| 07/24/21 | RHP Jerad Eickhoff elected free agency. |
| 07/24/21 | New York Mets recalled 2B Brandon Drury from Syracuse Mets. |
| 07/24/21 | New York Mets placed LHP David Peterson on the 60-day injured list. Right side soreness. |
| 07/24/21 | New York Mets optioned RHP Nick Tropeano to Syracuse Mets. |
| 07/24/21 | New York Mets optioned CF Mark Payton to Syracuse Mets. |
| 07/24/21 | New York Mets placed RHP Stephen Nogosek on the 10-day injured list. Right shoulder inflammation. |
| 07/24/21 | New York Mets activated LHP Rich Hill. |
| 07/24/21 | Cincinnati Reds traded CF Mark Payton to New York Mets for cash. |
| 07/23/21 | Tampa Bay Rays traded LHP Rich Hill to New York Mets for RHP Tommy Hunter and C Matt Dyer. |
| 07/23/21 | Tampa Bay Rays traded LHP Rich Hill to New York Mets for RHP Tommy Hunter and C Matt Dyer. |
| 07/23/21 | New York Mets signed RHP Mike Vasil. |
| 07/23/21 | Chicago Cubs claimed CF Johneshwy Fargas off waivers from New York Mets. |
| 07/23/21 | New York Mets placed RHP Robert Stock on the 60-day injured list. Right hamstring strain. |
| 07/23/21 | Tampa Bay Rays traded LHP Rich Hill to New York Mets for RHP Tommy Hunter and C Matt Dyer. |
| 07/22/21 | New York Mets signed free agent RHP Grant Hartwig to a minor league contract. |
| 07/22/21 | New York Mets signed LHP Nathan Lavender. |
| 07/21/21 | New York Mets signed OF Jack-Thomas Wold. |
| 07/21/21 | New York Mets optioned RHP Roel Ramirez to Syracuse Mets. |
| 07/21/21 | New York Mets claimed RHP Roel Ramirez off waivers from St. Louis Cardinals. |
| 07/21/21 | New York Mets signed LHP Nick Zwack. |
| 07/21/21 | New York Mets traded LF Billy McKinney to Los Angeles Dodgers for RF Carlos Rincon. |
| 07/21/21 | New York Mets recalled 3B Travis Blankenhorn from Syracuse Mets. |
| 07/21/21 | New York Mets optioned RHP Geoff Hartlieb to Syracuse Mets. |
| 07/21/21 | New York Mets placed RHP Robert Stock on the 10-day injured list. Right hamstring strain. |
| 07/21/21 | New York Mets signed SS Kevin Kendall. |
| 07/21/21 | New York Mets traded LF Billy McKinney to Los Angeles Dodgers for RF Carlos Rincon. |
| 07/21/21 | New York Mets recalled RHP Nick Tropeano from Syracuse Mets. |
| 07/20/21 | New York Mets sent RHP Carlos Carrasco on a rehab assignment to Syracuse Mets. |
| 07/20/21 | New York Mets signed LHP Keyshawn Askew. |
| 07/20/21 | New York Mets recalled RHP Geoff Hartlieb from Syracuse Mets. |
| 07/20/21 | New York Mets placed SS Jose Peraza on the 10-day injured list. Fractured right middle finger. |
| 07/20/21 | New York Mets signed RHP Carson Seymour. |
| 07/20/21 | New York Mets signed OF Rowdey Jordan. |
| 07/20/21 | New York Mets designated RHP Jerad Eickhoff for assignment. |
| 07/20/21 | New York Mets recalled RHP Robert Stock from Syracuse Mets. |
| 07/20/21 | New York Mets signed RHP Levi David. |
| 07/19/21 | New York Mets optioned 3B Travis Blankenhorn to Syracuse Mets. |
| 07/19/21 | New York Mets designated CF Johneshwy Fargas for assignment. |
| 07/19/21 | New York Mets selected the contract of RHP Stephen Nogosek from Syracuse Mets. |
| 07/19/21 | New York Mets signed SS Wyatt Young. |
| 07/19/21 | New York Mets selected the contract of LHP Anthony Banda from Syracuse Mets. |
| 07/19/21 | New York Mets placed RHP Corey Oswalt on the 60-day injured list. Right knee inflammation. |
| 07/18/21 | New York Mets placed RHP Jacob deGrom on the 10-day injured list. Right forearm tightness. |
| 07/18/21 | New York Mets signed RHP Kolby Kubichek. |
| 07/18/21 | New York Mets signed C Drake Osborn. |
| 07/18/21 | New York Mets signed SS Justin Guerrera. |
| 07/18/21 | New York Mets signed RHP Trey McLoughlin. |
| 07/18/21 | New York Mets signed 1B JT Schwartz. |
| 07/17/21 | New York Mets signed RHP Christian Scott. |
| 07/17/21 | New York Mets recalled 3B Travis Blankenhorn from Syracuse Mets. |
| 07/17/21 | New York Mets placed SS Francisco Lindor on the 10-day injured list. Right oblique strain. |
| 07/16/21 | New York Mets released LHP Stephen Tarpley. |
| 07/16/21 | New York Mets designated LF Billy McKinney for assignment. |
| 07/16/21 | New York Mets activated 3B J.D. Davis. |
| 07/14/21 | New York Mets sent RHP Carlos Carrasco on a rehab assignment to Brooklyn Cyclones. |
| 07/14/21 | New York Mets optioned CF Johneshwy Fargas to Binghamton Rumble Ponies. |
| 07/13/21 | New York Mets signed free agent RHP Douglas Orellana to a minor league contract. |
| 07/13/21 | New York Mets sent CF Johneshwy Fargas on a rehab assignment to Binghamton Rumble Ponies. |
| 07/11/21 | New York Mets optioned RHP Nick Tropeano to Syracuse Mets. |
| 07/11/21 | New York Mets designated LHP Stephen Tarpley for assignment. |
| 07/11/21 | New York Mets optioned RHP Geoff Hartlieb to Syracuse Mets. |
| 07/11/21 | New York Mets selected the contract of RHP Jerad Eickhoff from Syracuse Mets. |
| 07/10/21 | New York Mets recalled RHP Geoff Hartlieb from Syracuse Mets. |
| 07/09/21 | New York Mets claimed RHP Geoff Hartlieb off waivers from Pittsburgh Pirates. |
| 07/09/21 | New York Mets signed free agent RHP Brawny Reyes to a minor league contract. |
| 07/08/21 | New York Mets optioned RHP Robert Stock to Syracuse Mets. |
| 07/07/21 | New York Mets recalled RHP Nick Tropeano from Syracuse Mets. |
| 07/07/21 | New York Mets sent CF Johneshwy Fargas on a rehab assignment to St. Lucie Mets. |
| 07/06/21 | New York Mets placed RHP Corey Oswalt on the 10-day injured list. Right knee inflammation. |
| 07/06/21 | New York Mets recalled RHP Robert Stock from Syracuse Mets. |
| 07/05/21 | New York Mets optioned RHP Nick Tropeano to Syracuse Mets. |
| 07/04/21 | New York Mets activated SS Jonathan Villar. |
| 07/04/21 | New York Mets recalled RHP Nick Tropeano from Syracuse Mets. |
| 07/04/21 | New York Mets recalled RHP Yennsy Diaz from Syracuse Mets. |
| 07/04/21 | New York Mets placed RHP Sean Reid-Foley on the 10-day injured list. Right elbow inflammation. |
| 07/04/21 | New York Mets optioned CF Albert Almora Jr. to Syracuse Mets. |
| 07/03/21 | New York Mets sent RHP Jerad Eickhoff outright to Syracuse Mets. |
| 07/02/21 | New York Mets placed LHP David Peterson on the 10-day injured list. Right side soreness. |
| 07/02/21 | San Francisco Giants traded LHP Anthony Banda to New York Mets for 3B Will Toffey. |
| 07/02/21 | San Francisco Giants traded LHP Anthony Banda to New York Mets for 3B Will Toffey. |
| 07/02/21 | New York Mets activated RF Brandon Nimmo. |
| 07/02/21 | New York Mets activated RHP Jeurys Familia. |
| 07/02/21 | New York Mets activated RHP Marcus Stroman from the bereavement list. |
| 07/02/21 | New York Mets optioned LHP Thomas Szapucki to Syracuse Mets. |
| 07/02/21 | New York Mets optioned C Patrick Mazeika to Syracuse Mets. |
| 07/02/21 | New York Mets activated C Tomas Nido. |
| 07/02/21 | New York Mets optioned 3B Travis Blankenhorn to Syracuse Mets. |
| 07/01/21 | New York Mets signed free agent RHP Alex Sanabia to a minor league contract. |