diff --git a/sth-backend/src/main/java/hdm/mi/sthbackend/model/Team.java b/sth-backend/src/main/java/hdm/mi/sthbackend/model/Team.java
index 88d9e0b4c384908bd9539b2f657963908815bdb6..8d4e46a984ed0400128935fe6337b33b3e4635ca 100644
--- a/sth-backend/src/main/java/hdm/mi/sthbackend/model/Team.java
+++ b/sth-backend/src/main/java/hdm/mi/sthbackend/model/Team.java
@@ -11,10 +11,9 @@ import java.util.List;
 import java.util.UUID;
 
 @Getter
-@Document("Team")
 @AllArgsConstructor
 public class Team {
-    @Id
+
     private final UUID teamId;
     @Setter
     private String teamName;
diff --git a/sth-backend/src/main/java/hdm/mi/sthbackend/model/Tournament.java b/sth-backend/src/main/java/hdm/mi/sthbackend/model/Tournament.java
index 203ff94e93266c5617faaae476cd8f6b2af0d6ed..2ec62f31181f03c8ec82912dc0e3ca47b94ad3ad 100644
--- a/sth-backend/src/main/java/hdm/mi/sthbackend/model/Tournament.java
+++ b/sth-backend/src/main/java/hdm/mi/sthbackend/model/Tournament.java
@@ -23,7 +23,7 @@ public class Tournament implements ITournament{
     private String tournamentName;
     @Setter
     private List<BracketRound> bracket;
-    private List<Team> teams;
+    private Map<UUID, Team> teams;
     private List<UUID> users;
 
 
@@ -32,9 +32,7 @@ public class Tournament implements ITournament{
         this.tournamentId = UUID.randomUUID();
         this.tournamentName = tournamentName;
         this.bracket = new ArrayList<>();
-        this.teams = teamNames.stream().map( Team::new ).toList();
+        this.teams = teamNames.stream().map( Team::new ).collect(Collectors.toMap(Team::getTeamId, team -> team ));
     }
 
-    public Tournament(){};
-
 }
diff --git a/sth-backend/src/main/java/hdm/mi/sthbackend/repository/IMatchRepository.java b/sth-backend/src/main/java/hdm/mi/sthbackend/repository/IMatchRepository.java
deleted file mode 100644
index 9c7b2360b0a05ebe600ce979f411ce793b040731..0000000000000000000000000000000000000000
--- a/sth-backend/src/main/java/hdm/mi/sthbackend/repository/IMatchRepository.java
+++ /dev/null
@@ -1,9 +0,0 @@
-package hdm.mi.sthbackend.repository;
-
-import hdm.mi.sthbackend.model.Match;
-import org.springframework.data.mongodb.repository.MongoRepository;
-
-import java.util.UUID;
-
-public interface IMatchRepository extends MongoRepository<Match, UUID> {
-}
diff --git a/sth-backend/src/main/java/hdm/mi/sthbackend/repository/IPlayerRepository.java b/sth-backend/src/main/java/hdm/mi/sthbackend/repository/IPlayerRepository.java
deleted file mode 100644
index def782437cb1748269a22f1f390b1f7a973c39ee..0000000000000000000000000000000000000000
--- a/sth-backend/src/main/java/hdm/mi/sthbackend/repository/IPlayerRepository.java
+++ /dev/null
@@ -1,13 +0,0 @@
-package hdm.mi.sthbackend.repository;
-
-import hdm.mi.sthbackend.model.Player;
-import hdm.mi.sthbackend.model.Tournament;
-import org.springframework.data.mongodb.repository.MongoRepository;
-import org.springframework.stereotype.Repository;
-
-import java.util.UUID;
-
-@Repository
-public interface IPlayerRepository extends MongoRepository<Player, UUID> {
-
-}
diff --git a/sth-backend/src/main/java/hdm/mi/sthbackend/repository/ITeamRepository.java b/sth-backend/src/main/java/hdm/mi/sthbackend/repository/ITeamRepository.java
deleted file mode 100644
index e2bb9c3d526f8f8a9cdb06065fd23c914215184f..0000000000000000000000000000000000000000
--- a/sth-backend/src/main/java/hdm/mi/sthbackend/repository/ITeamRepository.java
+++ /dev/null
@@ -1,9 +0,0 @@
-package hdm.mi.sthbackend.repository;
-
-import hdm.mi.sthbackend.model.Team;
-import org.springframework.data.mongodb.repository.MongoRepository;
-
-import java.util.UUID;
-
-public interface ITeamRepository extends MongoRepository<Team, UUID> {
-}
diff --git a/sth-backend/src/main/java/hdm/mi/sthbackend/service/TournamentService.java b/sth-backend/src/main/java/hdm/mi/sthbackend/service/TournamentService.java
index dfa77feeb9e366abb96d8243f08c31762cff284b..8b69b4372e70902b405299cc1c092e636d942dfa 100644
--- a/sth-backend/src/main/java/hdm/mi/sthbackend/service/TournamentService.java
+++ b/sth-backend/src/main/java/hdm/mi/sthbackend/service/TournamentService.java
@@ -25,17 +25,16 @@ public class TournamentService {
     private final Logger log = LogManager.getLogger(TournamentService.class);
 
     ITournamentRepository tournamentRepository;
-    IPlayerRepository playerRepository;
-    ITeamRepository teamRepository;
-    IMatchRepository matchRepository;
 
     @Autowired
     ModelToDTOMapper mapper;
 
-    public PlayerDTO addPlayerToTeam(UUID teamId,
-                                  String playerName) throws TeamIdNotFoundException {
-        Team team = teamRepository.findById(teamId)
-                .orElseThrow(() -> new TeamIdNotFoundException(teamId));
+    public PlayerDTO addPlayerToTeam(UUID tournamentId, UUID teamId,
+                                  String playerName) throws TournamentIdNotFoundException, TeamIdNotFoundException {
+        Tournament tournament = tournamentRepository.findById(tournamentId)
+                .orElseThrow(() -> new TournamentIdNotFoundException( tournamentId));
+
+        Team team = Optional.ofNullable( tournament.getTeams().get( teamId )).orElseThrow(() -> new TeamIdNotFoundException(teamId)) ;
 
         Player newPlayer = new Player(UUID.randomUUID(), playerName);
         team.getTeamMembers()