Although Major League Baseball has made no indication of an intent to modify the crews based on region, as the League did during the 2020 regular season, MLB nonetheless reserves the right to shuffle the crews if operationally necessary.
2021 MLB Umpire Crews (by Umpiring Crew Chief Seniority)
| Crew # | Crew Chief | Umpire 2 | Umpire 3 | Umpire 4 |
|---|---|---|---|---|
| Crew 1 | 12 Davis, Gerry | 53 Gibson, Greg | 30 Drake, Rob | 93 Little, Will |
| Crew 2 | 22 West, Joe | 46 Kulpa, Ron | 1 Dreckman, Bruce | 59 Lentz, Nic |
| Crew 3 | 24 Layne, Jerry | 21 Wendelstedt, Hunter | 73 Gibson, Tripp | 81 Wolcott, Quinn |
| Crew 4 | 9 Gorman, Brian | 39 Nauert, Paul | 80 Johnson, Adrian | 74 Tumpane, John |
| Crew 5 | 20 Hallion Tom | 10 Cuzzi, Phil | 89 Blaser, Cory | 90 Ripperger, Mark |
| Crew 6 | 25 Culbreth, Fieldin | 7 O'Nora, Brian | 17 Reyburn, DJ | 36 Blakney, Ryan |
| Crew 7 | 65 Barrett, Ted | 5 Hernandez, Angel | 23 Barksdale, Lance | 85 Scheurwater, Stu |
| Crew 8 | 45 Nelson, Jeff | 63 Diaz, Laz | 79 Gonzalez, Manny | 83 Estabrook, Mike |
| Crew 9 | 26 Miller, Bill | 88 Eddings, Doug | 91 Knight, Brian | 47 Morales, Gabe |
| Crew 10 | 27 Vanover, Larry | 51 Hudson, Marvin | 2 Bellino, Dan | 86 Rackley, David |
| Crew 11 | 41 Meals, Jerry | 15 Hickox, Ed | 19 Carapazza, Vic | 52 Visconti, Jansen |
| Crew 12 | 50 Emmel, Paul | 3 Welke, Bill | 98 Conroy, Chris | 31 Hoberg, Pat |
| Crew 13 | 34 Holbrook, Sam | 60 Foster, Marty | 28 Wolf, Jim | 76 Muchlinski, Mike |
| Crew 14 | 14 Wegner, Mark | 68 Guccione, Chris | 64 Porter, Alan | 18 De Jesus, Ramon |
| Crew 15 | 44 Danley, Kerwin | 54 Bucknor, CB | 4 Fairchild, Chad | 78 Hamari, Adam |
| Crew 16 | 77 Reynolds, Jim | 11 Randazzo, Tony | 13 Tichenor, Todd | 62 Whitson, Chad |
| Crew 17 | 72 Marquez, Alfonso | 95 Timmons, Tim | 16 Barrett, Lance | 37 Torres, Carlos |
| Crew 18 | 58 Iassogna, Dan | 49 Fletcher, Andy | 87 Barry, Scott | 35 Rehak, Jeremie |
| Crew 19 | 6 Carlson, Mark | 92 Hoye, James | 71 Baker, Jordan | 96 Segal, Chris |
| DL/IR | TBD | CloseCallSports.com |
Umpires Promoted to Crew Chief 🔼: Mark Carlson.
Umpires Who Retired During the Off-Season 🔽: Mike Winters.
Notes and Observations:
≫ Only one crew—#17 (Marquez) is unchanged from the original crews for 2020 (pre-COVID).
≫ Layne reunites with longtime crewmate Wendelstedt (2010-16).
≫ T Barrett reunites with number two Hernandez (2015-17).
≫ Nelson keeps longtime number two Diaz (2014-present).
≫ Hallion keeps longtime number two Cuzzi (2016-present).
