diff --git a/src/data/ability.ts b/src/data/ability.ts
index 5d2ccfc9d36..3c71b880a98 100644
--- a/src/data/ability.ts
+++ b/src/data/ability.ts
@@ -3594,7 +3594,13 @@ export class PostTurnStatStageChangeAbAttr extends PostTurnAbAttr {
 
   applyPostTurn(pokemon: Pokemon, passive: boolean, simulated: boolean, args: any[]): boolean {
     if (!simulated) {
-      pokemon.scene.unshiftPhase(new StatStageChangePhase(pokemon.scene, pokemon.getBattlerIndex(), true, this.stats, this.stages));
+      if (!pokemon.hasAbility(Abilities.SPEED_BOOST)) {
+        pokemon.scene.unshiftPhase(new StatStageChangePhase(pokemon.scene, pokemon.getBattlerIndex(), true, this.stats, this.stages));
+      } else if (pokemon.hasAbility(Abilities.SPEED_BOOST) && !pokemon.turnData.switchedInThisTurn && !pokemon.turnData.failedRunAway) {
+        pokemon.scene.unshiftPhase(new StatStageChangePhase(pokemon.scene, pokemon.getBattlerIndex(), true, this.stats, this.stages));
+      } else {
+        this.showAbility = false;
+      }
     }
     return true;
   }
diff --git a/src/field/pokemon.ts b/src/field/pokemon.ts
index e52457851bb..b27e92fc204 100644
--- a/src/field/pokemon.ts
+++ b/src/field/pokemon.ts
@@ -105,8 +105,6 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
   public pauseEvolutions: boolean;
   public pokerus: boolean;
   public switchOutStatus: boolean;
-  public switchedInThisTurn: boolean;
-  public failedRunAway: boolean;
   public evoCounter: integer;
 
   public fusionSpecies: PokemonSpecies | null;
@@ -154,7 +152,6 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
     this.pokeball = dataSource?.pokeball || PokeballType.POKEBALL;
     this.level = level;
     this.switchOutStatus = false;
-    this.switchedInThisTurn = false;
 
     // Determine the ability index
     if (abilityIndex !== undefined) {
@@ -2254,10 +2251,6 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
     this.switchOutStatus = status;
   }
 
-  setSwitchedInStatus(status: boolean): void {
-    this.switchedInThisTurn = status;
-  }
-
   updateInfo(instant?: boolean): Promise<void> {
     return this.battleInfo.updateInfo(this, instant);
   }
@@ -5073,6 +5066,8 @@ export class PokemonTurnData {
   public statStagesDecreased: boolean = false;
   public moveEffectiveness: TypeDamageMultiplier | null = null;
   public combiningPledge?: Moves;
+  public switchedInThisTurn: boolean = false;
+  public failedRunAway: boolean = false;
 }
 
 export enum AiType {
diff --git a/src/phases/attempt-run-phase.ts b/src/phases/attempt-run-phase.ts
index 553c9899db9..44cb014083d 100644
--- a/src/phases/attempt-run-phase.ts
+++ b/src/phases/attempt-run-phase.ts
@@ -54,7 +54,7 @@ export class AttemptRunPhase extends PokemonPhase {
       this.scene.pushPhase(new BattleEndPhase(this.scene));
       this.scene.pushPhase(new NewBattlePhase(this.scene));
     } else {
-      playerPokemon.failedRunAway = true;
+      playerPokemon.turnData.failedRunAway = true;
       this.scene.queueMessage(i18next.t("battle:runAwayCannotEscape"), null, true, 500);
     }
 
diff --git a/src/phases/summon-phase.ts b/src/phases/summon-phase.ts
index 119e550293c..ed6a6ff8d46 100644
--- a/src/phases/summon-phase.ts
+++ b/src/phases/summon-phase.ts
@@ -238,7 +238,10 @@ export class SummonPhase extends PartyMemberPokemonPhase {
       this.scene.unshiftPhase(new ShinySparklePhase(this.scene, pokemon.getBattlerIndex()));
     }
 
+    /** Switch in status is set before the pokemon is summoned and the new turn begins, so it is preserved from switch-summon-phase */
+    const switchedInStatus = pokemon.turnData?.switchedInThisTurn;
     pokemon.resetTurnData();
+    pokemon.turnData.switchedInThisTurn = switchedInStatus;
 
     if (!this.loaded || [ BattleType.TRAINER, BattleType.MYSTERY_ENCOUNTER ].includes(this.scene.currentBattle.battleType) || (this.scene.currentBattle.waveIndex % 10) === 1) {
       this.scene.triggerPokemonFormChange(pokemon, SpeciesFormChangeActiveTrigger, true);
diff --git a/src/phases/switch-summon-phase.ts b/src/phases/switch-summon-phase.ts
index c3b22dadc79..137265d409a 100644
--- a/src/phases/switch-summon-phase.ts
+++ b/src/phases/switch-summon-phase.ts
@@ -106,9 +106,9 @@ export class SwitchSummonPhase extends SummonPhase {
     const switchedInPokemon = party[this.slotIndex];
     this.lastPokemon = this.getPokemon();
     if (this.switchType !== SwitchType.INITIAL_SWITCH) {
-      switchedInPokemon.setSwitchedInStatus(true);
+      switchedInPokemon.resetTurnData();
+      switchedInPokemon.turnData.switchedInThisTurn = true;
     }
-    this.lastPokemon.setSwitchedInStatus(false);
     applyPreSwitchOutAbAttrs(PreSwitchOutAbAttr, this.lastPokemon);
     if (this.switchType === SwitchType.BATON_PASS && switchedInPokemon) {
       (this.player ? this.scene.getEnemyField() : this.scene.getPlayerField()).forEach(enemyPokemon => enemyPokemon.transferTagsBySourceId(this.lastPokemon.id, switchedInPokemon.id));
diff --git a/src/phases/turn-end-phase.ts b/src/phases/turn-end-phase.ts
index 4c8e87b538b..60a2e6600db 100644
--- a/src/phases/turn-end-phase.ts
+++ b/src/phases/turn-end-phase.ts
@@ -10,7 +10,6 @@ import { TurnHealModifier, EnemyTurnHealModifier, EnemyStatusEffectHealChanceMod
 import i18next from "i18next";
 import { FieldPhase } from "./field-phase";
 import { PokemonHealPhase } from "./pokemon-heal-phase";
-import { Abilities } from "#app/enums/abilities";
 
 export class TurnEndPhase extends FieldPhase {
   constructor(scene: BattleScene) {
@@ -38,16 +37,7 @@ export class TurnEndPhase extends FieldPhase {
         this.scene.applyModifier(EnemyStatusEffectHealChanceModifier, false, pokemon);
       }
 
-      if (!pokemon.hasAbility(Abilities.SPEED_BOOST)) {
-        applyPostTurnAbAttrs(PostTurnAbAttr, pokemon);
-      } else if (pokemon.hasAbility(Abilities.SPEED_BOOST) && !pokemon.switchedInThisTurn && !pokemon.failedRunAway) {
-        pokemon.setSwitchedInStatus(false);
-        pokemon.failedRunAway = false;
-        applyPostTurnAbAttrs(PostTurnAbAttr, pokemon);
-      } else {
-        pokemon.failedRunAway = false;
-        pokemon.setSwitchedInStatus(false);
-      }
+      applyPostTurnAbAttrs(PostTurnAbAttr, pokemon);
 
       this.scene.applyModifiers(TurnStatusEffectModifier, pokemon.isPlayer(), pokemon);