| J. GallagherFull-back | Austin | 🇮🇪Republic of Ireland | 30 | 29 | 0 | 2 | 2.4 | 15▼27.2% | 25▼4.2% |
| J. GilmanCentre-back | Toronto FC | 🏳️ | 21 | 13 | 0 | 0 | 6.7 | 9 | 40 |
| J. GladFull-back | Real Salt Lake | 🇺🇸USA | 29 | 12 | 0 | 1 | 2.4 | 9▼70.1% | 25▼17% |
| J. GlesnesCentre-back | Los Angeles Galaxy | 🇳🇴Norway | 32 | 23 | 0 | 0 | 2.4 | 19▼65.5%↩ | 19▼14.7%↩ |
| J. GómezCentre-forward | Chicago Fire | 🇺🇸USA | 25 | 8 | 0 | 0 | 6.3 | 20±0% | 58±0% |
| J. GónzalezDefensive midfielder | San Jose Earthquakes | 🇲🇽Mexico | 27 | 11 | 0 | 0 | 5.3 | 4▲533.3%↩ | 28▼6.9%↩ |
| J. GregušCentral midfielder | Houston Dynamo | 🇸🇰Slovakia | 35 | 0 | 0 | 0 | 0.3 | 0▼100%↩ | 6▼62.3%↩ |
| J. GresselCentral midfielder | Minnesota United FC | 🇺🇸USA | 32 | 4 | 0 | 0 | 0.8 | 0▼100% | 11▼32.1% |
| J. GriffinCentre-back | Philadelphia Union | 🇺🇸USA | 18 | 1 | 0 | 0 | 4.8 | 0 | 36 |
| J. HaakDefensive midfielder | Los Angeles Galaxy | 🇺🇸USA | 25 | 30 | 2 | 1 | 11.9 | 30▼27.5%↩ | 43▼3.6%↩ |
| J. HallWinger | New York Red Bulls | 🇺🇸USA | 18 | 29 | 11 | 3 | 11.1 | 49▲920.8% | 56▲38.1% |
| J. HarrisonAttacking midfielder | New England Revolution | 🏴England | 29 | 7 | 0 | 3 | 3 | 11▼18.9%↩ | 23▼45%↩ |
| J. HopkinsCentral midfielder | DC United | 🇺🇸USA | 22 | 30 | 2 | 1 | 7.7 | 30▲104.1% | 45▲13.8% |
| J. LukićDefensive midfielder | Philadelphia Union | 🇷🇸Serbia | 24 | 28 | 0 | 2 | 9.9 | 26▼35% | 42▼4.5% |
| J. LynnCentre-forward | Orlando City SC | 🇺🇸USA | 26 | 0 | 0 | 0 | 5.4 | 0 | 29▼17.8% |
| J. MaherCentre-back | Nashville SC | 🇺🇸USA | 27 | 10 | 0 | 0 | 6.2 | 17▼9.6% | 34▼15.2% |
| J. MalatiniFull-back | FC Cincinnati | 🇦🇷Argentina | 25 | 2 | 0 | 0 | 6 | 6±0% | 59±0% |
| J. MarcinkowskiGoalkeeper | Los Angeles Galaxy | 🇺🇸USA | 29 | 25 | 0 | 0 | 3 | 7 | 28▲43.8% |
| J. Marshall-RuttyFull-back | New York Red Bulls | 🇨🇦Canada | 22 | 26 | 0 | 0 | 7.4 | 13▼50.2%↩ | 43±0% |
| J. MaurerGoalkeeper | Houston Dynamo | 🇺🇸USA | 38 | 1 | 0 | 0 | 0.1 | 0 | 2±0% |
| J. McCarthyGoalkeeper | New York Red Bulls | 🇺🇸USA | 34 | 12 | 0 | 0 | 0.8 | 2▼89.5%↩ | 13▼40.7%↩ |
| J. MensahCentre-back | New England Revolution | 🇬🇭Ghana | 36 | 0 | 0 | 0 | 0.3 | 0▼100%↩ | 6▼64.3%↩ |
| J. MijatovićWinger | New York City FC | 🇷🇸Serbia | 21 | 14 | 0 | 1 | 8.7 | 7▼12.3%↩ | 51▼8.6%↩ |
| J. MinaCentre-back | New York Red Bulls | 🇨🇴Colombia | 22 | 5 | 0 | 0 | 6.3 | 2 | 36▼27.8%↩ |
| J. MorrisCentre-forward | Seattle Sounders | 🇺🇸USA | 32 | 21 | 2 | 4 | 2.7 | 14▼34.9% | 17▼7.4% |
| J. MosqueraFull-back | Portland Timbers | 🇨🇴Colombia | 24 | 3 | 1 | 1 | 6.9 | 1▼95% | 38▼10.6% |
| J. MussendenCentral midfielder | New England Revolution | 🏳️ | 18 | 1 | 0 | 0 | 5.1 | 0 | 36 |
| J. NealCentre-back | CF Montreal | 🇺🇸USA | 23 | 19 | 0 | 0 | 7.7 | 12▲2.6% | 40▲6.6% |
| J. NeeleyCentre-back | Charlotte | 🇺🇸USA | 21 | 1 | 0 | 0 | 5.9 | 0 | 35 |
| J. NelsonCentre-back | Los Angeles Galaxy | 🇺🇸USA | 28 | 27 | 0 | 0 | 3.4 | 11▼13.4% | 29▼1.7% |
| J. NerwinskiCentre-back | St. Louis City | 🇺🇸USA | 32 | 0 | 0 | 0 | 0.8 | 0▼100% | 13▼57.9% |
| J. OrozcoCentre-back | St. Louis City | 🇺🇸USA | 22 | 21 | 0 | 0 | 9.3 | 19▲128.2% | 42▲13.6% |
| J. OrtizCentral midfielder | Portland Timbers | 🇪🇨Ecuador | 30 | 21 | 0 | 1 | 1.9 | 11▲55.9% | 20▲1.5% |
| J. OsorioCentral midfielder | Toronto FC | 🇨🇦Canada | 34 | 21 | 0 | 4 | 1.3 | 29▲51.5% | 15▲11% |
| J. PaintsilAttacking midfielder | Los Angeles Galaxy | 🇬🇭Ghana | 28 | 23 | 5 | 3 | 5.1 | 34▼5.8% | 33▲7.8% |
| J. PalaciosCentre-back | Nashville SC | 🇨🇴Colombia | 32 | 24 | 1 | 1 | 2.5 | 49▲112.5% | 20▲9.9% |
| J. PantemisGoalkeeper | Portland Timbers | 🇨🇦Canada | 29 | 30 | 0 | 0 | 3.2 | 1▼90.2% | 31▲15.9% |
| J. PereyraWinger | Minnesota United FC | 🇦🇷Argentina | 27 | 28 | 3 | 11 | 11.7 | 43▲5.9% | 40▼2.9% |
| J. PulskampGoalkeeper | Sporting Kansas City | 🇺🇸USA | 25 | 9 | 0 | 0 | 6.3 | 0▼100% | 35▼17.9% |
| J. RafanelloCentral midfielder | Philadelphia Union | 🇺🇸USA | 26 | 5 | 0 | 0 | 5.7 | 1▼31.6% | 30▼0.7% |
| J. RagenCentre-back | Seattle Sounders | 🇺🇸USA | 28 | 22 | 0 | 0 | 4.9 | 23▼1.7% | 34▲6.3% |
| J. ReidDefensive midfielder | Sporting Kansas City | 🇺🇸USA | 25 | 20 | 0 | 0 | 6.6 | 13▲131%↩ | 36▲8.8%↩ |
| J. ReidCentre-back | Sporting Kansas City | 🏴England | 25 | 1 | 0 | 0 | 5.7 | 0 | 30▲11%↩ |
| J. ReynoldsFull-back | Sporting Kansas City | 🇺🇸USA | 22 | 16 | 1 | 2 | 7.5 | 8▲2600%↩ | 37▲1.6%↩ |
| J. RickettsCentral midfielder | San Jose Earthquakes | 🇺🇸USA | 25 | 27 | 0 | 2 | 8.1 | 25▲51.2% | 44▲15.5% |
| J. RosalesCentral midfielder | Austin | 🇭🇳Honduras | 25 | 27 | 1 | 4 | 11.6 | 39▲114.2%↩ | 42▲2.2%↩ |
| J. RuvalcabaCentre-forward | New York Red Bulls | 🇲🇽Mexico | 25 | 29 | 8 | 1 | 10.9 | 36▲58%↩ | 44▼11.9%↩ |
| J. SanabriaCentral midfielder | Real Salt Lake | 🇺🇾Uruguay | 26 | 25 | 1 | 5 | 11.2 | 39▲132.1%↩ | 39▼10.3%↩ |
| J. SandsCentre-back | New York City FC | 🇺🇸USA | 26 | 15 | 1 | 0 | 7.8 | 9▼68.6%↩ | 35▼44.7%↩ |
| J. SargentCentre-forward | Toronto FC | 🇺🇸USA | 26 | 23 | 7 | 2 | 10.1 | 37▲40.1%↩ | 40▼32.4%↩ |
| J. Sery LarsenCentre-back | Philadelphia Union | 🇩🇰Denmark | 26 | 14 | 1 | 0 | 7.9 | 14▲33.6%↩ | 35▼3.3%↩ |
| J. ShaffelburgWinger | Los Angeles FC | 🇨🇦Canada | 26 | 19 | 0 | 4 | 6.6 | 9▼50.9%↩ | 35▼3%↩ |
| J. ShannonCentre-back | Chicago Fire | 🇺🇸USA | 26 | 0 | 0 | 0 | 5.4 | 0 | 29 |
| J. ShoreDefensive midfielder | New York City FC | 🇺🇸USA | 19 | 20 | 0 | 0 | 5.9 | 7▼63.3% | 39▼6.7% |
| J. SiqueiraCentre-forward | New England Revolution | 🏳️ | 16 | 3 | 0 | 0 | 4.4 | 0 | 37 |
| J. SiroisGoalkeeper | FC Dallas | 🇨🇦Canada | 25 | 11 | 0 | 0 | 8.1 | 6▲64.1%↩ | 39▼5.6%↩ |
| J. SkahanAttacking midfielder | San Jose Earthquakes | 🇺🇸USA | 28 | 21 | 2 | 2 | 3.3 | 17▲453.3% | 29▲20.5% |
| J. SkinnerCentre-back | Charlotte | 🇺🇸USA | 23 | 9 | 0 | 0 | 5.3 | 4▲3900%↩ | 28▼16.8%↩ |
| J. StroudCentral midfielder | DC United | 🇺🇸USA | 30 | 21 | 1 | 0 | 1.8 | 11▲50.7% | 20▼7% |
| J. ThiaréCentre-forward | Columbus Crew | 🇸🇳Senegal | 33 | 16 | 2 | 0 | 0.8 | 6▼66.5%↩ | 10▼20.7%↩ |
| J. TravisFull-back | Colorado Rapids | 🇺🇸USA | 22 | 15 | 0 | 1 | 7 | 18▲293.3% | 42▲11.1% |
| J. TverskovDefensive midfielder | San Diego | 🇩🇰Denmark | 33 | 24 | 0 | 3 | 1.8 | 27▼47.1% | 16▼26.2% |
| J. ValienteAttacking midfielder | FC Dallas | 🇺🇾Uruguay | 25 | 28 | 2 | 9 | 10.2 | 31 | 44 |
| J. VilsaintWinger | Toronto FC | 🇨🇦Canada | 23 | 4 | 0 | 0 | 6.4 | 0▼100%↩ | 35▼9.2%↩ |
| J. WatermanCentre-back | Portland Timbers | 🇨🇦Canada | 30 | 16 | 1 | 0 | 1.9 | 0▼100%↩ | 16▼35.9%↩ |
| J. WillisGoalkeeper | Nashville SC | 🇺🇸USA | 38 | 1 | 0 | 0 | 0.1 | 17±0% | 14±0% |
| J. WynderCentre-back | New England Revolution | 🇺🇸USA | 21 | 6 | 1 | 0 | 6.6 | 1±0% | 43±0% |
| J. YaroCentre-back | St. Louis City | 🇬🇭Ghana | 31 | 18 | 1 | 0 | 2.3 | 17▲70.4% | 22▼4.7% |
| J. YueillCentral midfielder | New England Revolution | 🇺🇸USA | 29 | 19 | 0 | 2 | 2.4 | 3▼40.8% | 21▼6.2% |
| Jack JasinskiCentre-back | San Jose Earthquakes | 🇺🇸USA | 22 | 17 | 2 | 0 | 7.5 | 12 | 40 |
| Jansen MillerCentre-back | Sporting Kansas City | 🇺🇸USA | 24 | 16 | 0 | 0 | 6.7 | 4▼76.9% | 35▼13.9% |
| Jason ShokalookCentre-forward | Real Salt Lake | 🇺🇸USA | 24 | 13 | 0 | 0 | 6.3 | 0▼100%↩ | 34▼1.7%↩ |
| Javier OteroGoalkeeper | Orlando City SC | 🇻🇪Venezuela | 23 | 2 | 0 | 0 | 6.6 | 0 | 35▲0.6% |
| Jayden HibbertGoalkeeper | Atlanta United FC | 🇯🇲Jamaica | 22 | 8 | 0 | 0 | 7.4 | 4 | 43 |
| JD GunnCentre-forward | New England Revolution | 🇵🇦Panama | 26 | 1 | 0 | 0 | 5.4 | 0 | 29 |
| Jeong Ho-YeonDefensive midfielder | Minnesota United FC | 🇰🇷Korea Republic | 26 | 4 | 0 | 0 | 5.4 | 2▼78.7%↩ | 32▼38.8%↩ |
| Jeong Sang-BinCentre-forward | St. Louis City | 🇰🇷Korea Republic | 24 | 22 | 3 | 1 | 7.8 | 15▲41.7% | 41▲14.2% |
| Jesús Rafael Barea BarrosoWinger | Real Salt Lake | 🇪🇸Spain | 24 | 3 | 0 | 0 | 6.1 | 0 | 33▼3.8% |
| João KlaussCentre-forward | Los Angeles Galaxy | 🇧🇷Brazil | 29 | 12 | 7 | 0 | 3.6 | 20▼48.8%↩ | 24▼17.4%↩ |
| Johnny SelemaniWinger | Vancouver Whitecaps | 🇨🇦Canada | 18 | 1 | 0 | 0 | 5.4 | 0 | 39▲1.3% |
| Joran GerbetCentral midfielder | Orlando City SC | 🇫🇷France | 25 | 9 | 0 | 1 | 6.7 | 2▼83.6% | 33▼9.5% |
| Jorge AlastueyCentral midfielder | Austin | 🇪🇸Spain | 23 | 13 | 0 | 0 | 6.6 | 4 | 35 |
| Josef MartínezCentre-forward | Columbus Crew | 🇻🇪Venezuela | 33 | 11 | 1 | 1 | 0.8 | 0▼100%↩ | 9▼45.6%↩ |
| Joshua TorquatoCentre-back | FC Dallas | 🇺🇸USA | 19 | 1 | 0 | 0 | 5.7 | 0▼94.7% | 38▲1.1% |
| Joyeux Masanka BungiDefensive midfielder | New York Red Bulls | 🇧🇪Belgium | 19 | 2 | 0 | 0 | 5.5 | 2 | 37 |
| Jude TerryAttacking midfielder | Los Angeles FC | 🇺🇸USA | 18 | 12 | 2 | 1 | 6 | 7 | 43 |
| Justin EllisWinger | Orlando City SC | 🇺🇸USA | 19 | 21 | 1 | 9 | 9.6 | 26 | 44▲22.8% |
| K. AgyabengDefensive midfielder | Sporting Kansas City | 🏳️ | 19 | 21 | 0 | 0 | 5.8 | 9 | 37 |
| K. CabreraWinger | Vancouver Whitecaps | 🇵🇪Peru | 23 | 9 | 0 | 2 | 7.5 | 7▲48% | 39▲0.8% |
| K. ChandlerCentre-back | Minnesota United FC | 🇺🇸USA | 21 | 1 | 0 | 0 | 5.7 | 0▼100% | 35▼5.5% |
| K. DenkeyCentre-forward | FC Cincinnati | 🇹🇬Togo | 25 | 27 | 17 | 3 | 14.4 | 57▲22.3% | 47▲4% |
| K. DuncanFull-back | Minnesota United FC | 🇺🇸USA | 29 | 24 | 1 | 2 | 2.8 | 20▼15.6%↩ | 28▲4.8%↩ |
| K. FletcherWinger | FC Cincinnati | 🇺🇸USA | 21 | 2 | 0 | 0 | 6 | 0 | 36▲0.8%↩ |
| K. FranklinFull-back | Toronto FC | 🇨🇦Canada | 23 | 20 | 2 | 2 | 8 | 19▲119.3% | 44▲16.8% |
| K. FuruhashiWinger | Los Angeles Galaxy | 🇯🇵Japan | 31 | 11 | 0 | 0 | 1.3 | 0▼100%↩ | 15▼41%↩ |
| K. HenryCentre-back | Real Salt Lake | 🇺🇸USA | 22 | 10 | 0 | 0 | 6.8 | 4▲3900% | 35▲2% |
| K. HiebertCentre-back | St. Louis City | 🇨🇦Canada | 29 | 22 | 1 | 1 | 3.3 | 19▲24% | 31▼3.5% |
| K. KahlinaGoalkeeper | Charlotte | 🇭🇷Croatia | 34 | 30 | 0 | 0 | 1 | 15▼61.8% | 18▲2.3% |
| K. Kossa-RienziCentral midfielder | Seattle Sounders | 🇺🇸USA | 24 | 28 | 3 | 0 | 9.7 | 37▲97.3% | 43±0% |
| K. KurokawaFull-back | DC United | 🇯🇵Japan | 29 | 30 | 0 | 6 | 4.7 | 31▲5.4%↩ | 33▼12.4%↩ |