Team fielding -- 2021 Seattle Mariners
Regular season -- as of 10/19/2021
| Primary |
| Pos | S | Name | G | GS | INN | PO | A | E | DP | TC | PCT | PB | SB | CS | SB% | PK |
| p | f | Erick Fedde | 35 | 22 | 143.3 | 12 | 28 | 0 | 0 | 40 | 1.000 | | 14 | 6 | .700 | 3 |
| | | Tyler Glasnow | 33 | 33 | 186.7 | 13 | 19 | 1 | 1 | 33 | .970 | | 20 | 2 | .909 | 0 |
| | | Mike Minor | 33 | 33 | 182.7 | 15 | 11 | 3 | 0 | 29 | .897 | | 9 | 5 | .643 | 1 |
| | | Jose Urquidy | 17 | 17 | 105.3 | 7 | 11 | 1 | 1 | 19 | .947 | | 5 | 4 | .556 | 1 |
| | | Nick Margevicius | 31 | 1 | 81.0 | 6 | 12 | 0 | 1 | 18 | 1.000 | | 2 | 1 | .667 | 0 |
| | | Tarik Skubal | 25 | 23 | 114.7 | 3 | 11 | 0 | 0 | 14 | 1.000 | | 12 | 0 | 1.000 | 0 |
| | | Burch Smith | 18 | 0 | 55.7 | 3 | 10 | 0 | 0 | 13 | 1.000 | | 0 | 2 | .000 | 1 |
| | | Matt Wisler | 54 | 11 | 104.7 | 8 | 4 | 1 | 0 | 13 | .923 | | 6 | 3 | .667 | 0 |
| | f | Colin Rea | 11 | 4 | 34.3 | 6 | 6 | 0 | 0 | 12 | 1.000 | | 2 | 0 | 1.000 | 0 |
| | | Richard Rodriguez | 69 | 0 | 89.0 | 6 | 4 | 2 | 1 | 12 | .833 | | 2 | 2 | .500 | 0 |
| | | Tony Watson | 52 | 0 | 61.3 | 7 | 5 | 0 | 0 | 12 | 1.000 | | 2 | 0 | 1.000 | 0 |
| | | Brad Keller | 9 | 9 | 64.0 | 2 | 9 | 0 | 2 | 11 | 1.000 | | 2 | 0 | 1.000 | 0 |
| | | Darren O'Day | 52 | 0 | 55.0 | 2 | 6 | 1 | 0 | 9 | .889 | | 3 | 0 | 1.000 | 0 |
| | | Jake Diekman | 56 | 0 | 60.3 | 4 | 2 | 1 | 1 | 7 | .857 | | 1 | 1 | .500 | 0 |
| | | Miguel Castro | 43 | 0 | 53.7 | 1 | 4 | 0 | 0 | 5 | 1.000 | | 6 | 2 | .750 | 0 |
| | | Sam Freeman | 10 | 0 | 12.0 | 0 | 3 | 0 | 0 | 3 | 1.000 | | 0 | 0 | .000 | 0 |
| | | Other | 9 | 9 | 52.3 | 2 | 4 | 1 | 1 | 7 | .857 | | 1 | 0 | 1.000 | 0 |
| | | Total | 557 | 162 | 1456.0 | 97 | 149 | 11 | 8 | 257 | .957 | | 87 | 28 | .757 | 6 |
| | | | | | | | | | | | | | | | | |
| c | | Travis d'Arnaud | 112 | 112 | 1009.7 | 1123 | 32 | 7 | 3 | 1162 | .994 | 15 | 62 | 18 | .775 | 1 |
| | | Francisco Cervelli | 44 | 42 | 378.3 | 377 | 17 | 2 | 3 | 396 | .995 | 3 | 23 | 10 | .697 | 0 |
| | f | William Contreras | 8 | 8 | 68.0 | 78 | 1 | 0 | 0 | 79 | 1.000 | 0 | 2 | 0 | 1.000 | 0 |
| | | Total | 164 | 162 | 1456.0 | 1578 | 50 | 9 | 6 | 1637 | .995 | 18 | 87 | 28 | .757 | 1 |
| | | | | | | | | | | | | | | | | |
| 1b | | Pete Alonso | 152 | 152 | 1354.0 | 1220 | 104 | 17 | 94 | 1341 | .987 | | | | | |
| | | Tommy La Stella | 10 | 10 | 85.0 | 76 | 7 | 0 | 7 | 83 | 1.000 | | | | | |
| | f | Phillip Evans | 3 | 0 | 10.0 | 11 | 0 | 0 | 1 | 11 | 1.000 | | | | | |
| | f | Derek Dietrich | 1 | 0 | 3.0 | 2 | 0 | 0 | 1 | 2 | 1.000 | | | | | |
| | | Ian Happ | 1 | 0 | 2.0 | 1 | 0 | 0 | 0 | 1 | 1.000 | | | | | |
| | | DJ LeMahieu | 1 | 0 | 2.0 | 1 | 0 | 0 | 0 | 1 | 1.000 | | | | | |
| | | Total | 168 | 162 | 1456.0 | 1311 | 111 | 17 | 103 | 1439 | .988 | | | | | |
| | | | | | | | | | | | | | | | | |
| 2b | | DJ LeMahieu | 115 | 111 | 1006.3 | 152 | 316 | 9 | 51 | 477 | .981 | | | | | |
| | f | Christian Arroyo | 32 | 31 | 283.0 | 60 | 97 | 1 | 23 | 158 | .994 | | | | | |
| | | Tommy La Stella | 17 | 17 | 127.7 | 25 | 29 | 2 | 8 | 56 | .964 | | | | | |
| | | Kyle Farmer | 10 | 3 | 37.0 | 7 | 7 | 0 | 1 | 14 | 1.000 | | | | | |
| | | Whit Merrifield | 1 | 0 | 2.0 | 2 | 1 | 0 | 1 | 3 | 1.000 | | | | | |
| | | Total | 175 | 162 | 1456.0 | 246 | 450 | 12 | 84 | 708 | .983 | | | | | |
| | | | | | | | | | | | | | | | | |
| 3b | | Tommy La Stella | 82 | 60 | 576.3 | 30 | 92 | 11 | 5 | 133 | .917 | | | | | |
| | | Kyle Farmer | 66 | 51 | 439.0 | 18 | 96 | 9 | 8 | 123 | .927 | | | | | |
| | f | Phillip Evans | 21 | 21 | 178.0 | 6 | 37 | 3 | 5 | 46 | .935 | | | | | |
| | | DJ LeMahieu | 25 | 25 | 202.7 | 7 | 34 | 3 | 3 | 44 | .932 | | | | | |
| | f | Christian Arroyo | 10 | 5 | 60.0 | 3 | 7 | 0 | 0 | 10 | 1.000 | | | | | |
| | | Total | 204 | 162 | 1456.0 | 64 | 266 | 26 | 21 | 356 | .927 | | | | | |
| | | | | | | | | | | | | | | | | |
| ss | | Javier Baez | 159 | 159 | 1419.0 | 148 | 467 | 15 | 67 | 630 | .976 | | | | | |
| | | Kyle Farmer | 5 | 3 | 37.0 | 5 | 18 | 0 | 6 | 23 | 1.000 | | | | | |
| | | Total | 164 | 162 | 1456.0 | 153 | 485 | 15 | 73 | 653 | .977 | | | | | |
| | | | | | | | | | | | | | | | | |
| lf | | Adam Engel | 93 | 93 | 830.0 | 186 | 6 | 6 | 1 | 198 | .970 | | | | | |
| | | Alex Dickerson | 60 | 57 | 508.0 | 103 | 1 | 2 | 0 | 106 | .981 | | | | | |
| | f | Phillip Evans | 8 | 8 | 65.0 | 11 | 0 | 0 | 0 | 11 | 1.000 | | | | | |
| | | Luis Alexande Basabe | 11 | 4 | 53.0 | 9 | 0 | 0 | 0 | 9 | 1.000 | | | | | |
| | | Total | 172 | 162 | 1456.0 | 309 | 7 | 8 | 1 | 324 | .975 | | | | | |
| | | | | | | | | | | | | | | | | |
| cf | | Ian Happ | 151 | 151 | 1336.3 | 278 | 7 | 8 | 0 | 293 | .973 | | | | | |
| | | Adam Engel | 13 | 11 | 110.7 | 25 | 2 | 0 | 0 | 27 | 1.000 | | | | | |
| | | Luis Alexande Basabe | 3 | 0 | 7.0 | 3 | 0 | 0 | 0 | 3 | 1.000 | | | | | |
| | | Whit Merrifield | 1 | 0 | 2.0 | 0 | 0 | 0 | 0 | 0 | .000 | | | | | |
| | | Total | 168 | 162 | 1456.0 | 306 | 9 | 8 | 0 | 323 | .975 | | | | | |
| | | | | | | | | | | | | | | | | |
| rf | | Whit Merrifield | 162 | 162 | 1447.0 | 303 | 3 | 2 | 2 | 308 | .994 | | | | | |
| | | Luis Alexande Basabe | 4 | 0 | 9.0 | 1 | 1 | 0 | 0 | 2 | 1.000 | | | | | |
| | | Total | 166 | 162 | 1456.0 | 304 | 4 | 2 | 2 | 310 | .994 | | | | | |
| | | | | | | | | | | | | | | | | |
| | | Total | 162 | 162 | 1456.0 | 4368 | 1531 | 108 | 107 | 6007 | .982 | 18 | | | | |