UsagePosition -- 2021 Seattle Mariners
Regular season -- as of 10/19/2021
| Batter Status |
| S | Name | P | G | FLG |
| | Pete Alonso | 1b | 154 | 152 |
| f | Christian Arroyo | 2b | 41 | 42 |
| | Javier Baez | ss | 159 | 159 |
| | Luis Alexande Basabe | rf | 24 | 27 |
| | Miguel Cabrera | dh | 159 | 85 |
| | Francisco Cervelli | c | 43 | 45 |
| f | William Contreras | c | 11 | 8 |
| | Charlie Culberson | 1b | 24 | 1 |
| | Travis d'Arnaud | c | 119 | 121 |
| | Alex Dickerson | lf | 140 | 127 |
| f | Derek Dietrich | dh | 68 | 33 |
| | Adam Engel | rf | 97 | 104 |
| f | Phillip Evans | 3b | 30 | 29 |
| | Kyle Farmer | ss | 86 | 83 |
| | Ian Happ | cf | 154 | 151 |
| | Tommy La Stella | 2b | 149 | 123 |
| | DJ LeMahieu | 2b | 135 | 136 |
| | Whit Merrifield | rf | 162 | 162 |
| | Total | | 1755 | 1588 |
| Pitcher Status |
| S | Name | P | G | FLG | GS | FLGS |
| | Tyler Glasnow | sp | 30 | 33 | 30 | 33 |
| | Mike Minor | sp | 32 | 33 | 30 | 33 |
| | Brad Keller | sp | 24 | 27 | 24 | 27 |
| f | Erick Fedde | sp | 30 | 35 | 22 | 22 |
| | Tarik Skubal | sp | 22 | 25 | 20 | 23 |
| | Nick Margevicius | sp | 27 | 31 | 19 | 1 |
| | Jose Urquidy | sp | 14 | 17 | 14 | 17 |
| | Matt Wisler | mr | 49 | 54 | 11 | 11 |
| f | Colin Rea | mr | 24 | 11 | 5 | 4 |
| | Darren O'Day | mr | 51 | 52 | 0 | 0 |
| | Miguel Castro | mr | 70 | 43 | 0 | 0 |
| | Richard Rodriguez | mr | 65 | 69 | 0 | 0 |
| f | Tommy Kahnle | mr | 3 | 0 | 0 | 0 |
| | Jake Diekman | mr | 57 | 56 | 0 | 0 |
| f | Zack Littell | mr | 16 | 0 | 0 | 0 |
| f | Corey Knebel | mr | 41 | 0 | 0 | 0 |
| | Tony Watson | mr | 57 | 52 | 0 | 0 |
| | Burch Smith | mr | 16 | 18 | 0 | 0 |
| f | Javy Guerra | mr | 38 | 0 | 0 | 0 |
| | Sam Freeman | mr | 19 | 10 | 0 | 0 |
| f | Jon Duplantier | mr | 0 | 0 | 0 | 0 |
| | Total | | 175 | 171 | 175 | 171 |