diff --git a/server/management/commands/open_or_close_tournament_registrations.py b/server/management/commands/open_or_close_tournament_registrations.py
index 68fe3cc6..67f25c82 100644
--- a/server/management/commands/open_or_close_tournament_registrations.py
+++ b/server/management/commands/open_or_close_tournament_registrations.py
@@ -3,13 +3,11 @@
 from django.core.management.base import BaseCommand
 from django.utils.timezone import now
 
-from server.tournament.models import Tournament
+from server.tournament.models import Registration, Tournament
 
 
 class Command(BaseCommand):
-    help = (
-        "Check if registrations are open or closed today, and update tournament status accordingly"
-    )
+    help = "Check if registrations are open or closed today, and update tournament status accordingly. Also update registration's player teams on day of tournament"
 
     def handle(self, *args: Any, **options: Any) -> None:
         today = now().date()
@@ -26,3 +24,13 @@ def handle(self, *args: Any, **options: Any) -> None:
 
         if team_registrations_closed_today.count() > 0:
             team_registrations_closed_today.update(status=Tournament.Status.SCHEDULING)
+
+        tournaments_that_starts_today = Tournament.objects.filter(
+            event__start_date__exact=today, status=Tournament.Status.LIVE
+        )
+
+        for tournament in tournaments_that_starts_today:
+            registrations = Registration.objects.filter(event=tournament.event)
+
+            for reg in registrations:
+                reg.player.teams.add(reg.team)
diff --git a/server/migrations/0091_backfill_team_to_player_from_registrations.py b/server/migrations/0091_backfill_team_to_player_from_registrations.py
new file mode 100644
index 00000000..67fc2c38
--- /dev/null
+++ b/server/migrations/0091_backfill_team_to_player_from_registrations.py
@@ -0,0 +1,29 @@
+from django.db import migrations
+from django.db.backends.base.schema import BaseDatabaseSchemaEditor
+from django.db.migrations.state import StateApps
+
+
+def add_team_to_player_from_registrations(
+    apps: StateApps, schema_editor: BaseDatabaseSchemaEditor
+) -> None:
+    SeriesRegistration = apps.get_model("server", "SeriesRegistration")  # noqa: N806
+    series_registrations = SeriesRegistration.objects.all()
+
+    Registration = apps.get_model("server", "Registration")  # noqa: N806
+    registrations = Registration.objects.all()
+
+    for series_registration in series_registrations:
+        series_registration.player.teams.add(series_registration.team)
+
+    for registration in registrations:
+        registration.player.teams.add(registration.team)
+
+
+class Migration(migrations.Migration):
+    dependencies = [("server", "0090_alter_player_teams")]
+
+    operations = [
+        migrations.RunPython(
+            code=add_team_to_player_from_registrations, reverse_code=migrations.RunPython.noop
+        )
+    ]