UnboundLocalError: local variable 'player' referenced before assignment(pygame)

Question

Here is a part of my code for a game:

current_ship = 'player'


def main():
    global current_ship

    run = True
    FPS = 120
    clock = pg.time.Clock()
    level = 0
    lives = 3
    main_font = pg.font.SysFont('Algerian',30)
    lost_font = pg.font.SysFont('Algerian', 80)
    ship_speed = 3
    alien_lazer_speed = 4
    lazer_speed = 7

    aliens = []
    wave_length = 5
    alien_speed = .5

    if current_ship == 'player':     # Ships
        player = Player(900,800)

    elif current_ship ==' player1':
        player = Player_1(900,800)



    lost = False
    lost_count = 0

    def redraw_window():
        WIN.blit(BG,(0,0))

        level_label = main_font.render(f"Level: {level}",1,(255,255,255))

        WIN.blit(level_label,(WIDTH - level_label.get_width() - 20,10))

        # Here to draw the player lives
        if lives == 3:
            WIN.blit(player_ship_image_resize,(0,0))
            WIN.blit(player_ship_image_resize, (73,0))
            WIN.blit(player_ship_image_resize, (146, 0))
        if lives == 2:
            WIN.blit(player_ship_image_resize,(0,0))
            WIN.blit(player_ship_image_resize, (73,0))

        if lives == 1:
            WIN.blit(player_ship_image_resize, (0, 0))


        for alien in aliens:
            alien.draw(WIN)

        player.draw(WIN)

        if lost:
            lost_label = lost_font.render("Game Over" ,1,(255,0,0))
            WIN.blit(lost_label,(WIDTH/2 - lost_label.get_width()/2,350))


        pg.display.update()

    while run:
        clock.tick(FPS)

        if lives <= 0 or player.health <= 0:   # ERROR RIGHT HERE
            lost = True
            lost_count += 1

        if len(aliens) == 0:

            level += 1

            level_up.play()
            wave_length += 5
            for i in range(wave_length):
                #Right here
                alien = Alien(random.randrange(50,WIDTH-100),random.randrange(-2500,-100),random.choice(["red","yellow","gray"]))
                aliens.append(alien)

        for event in pg.event.get():
            if event.type == pg.QUIT:
                quit()

        keys = pg.key.get_pressed()
        if keys[pg.K_a] and player.x - ship_speed > 0:
            player.x -= ship_speed
        if keys[pg.K_d] and player.x + ship_speed + player.get_width() < WIDTH:
            player.x += ship_speed
        if keys[pg.K_w] and player.y - ship_speed > 0:
            player.y -= ship_speed
        if keys[pg.K_s] and player.y + ship_speed + player.get_height() < HEIGHT:
            player.y += ship_speed

        # player lazer
        if keys[pg.K_SPACE]:
            player.shoot()

            pew_1.play()



        for alien in aliens[:]:
            alien.move(alien_speed)
            alien.move_lazers(alien_lazer_speed,player)

            if random.randrange(0,3*120) == 1:
                alien.shoot()


            if collide(alien,player):
                player.health -= 20
                explosion_small.play()
                aliens.remove(alien)

            elif alien.y + alien.get_height() > HEIGHT:
                lives -= 1
                aliens.remove(alien)

        player.move_lazers(-lazer_speed,aliens)

        redraw_window()

The error is in line 68: "if lives <= 0 or player.health <= 0:", but I have no idea why that becomes an issue. The varible is defined by an if statement, I don't know if that is the correct why to do it, but the varible player here isn't defined outside the function, so why do I got an UnboundLocalError? The error dissappears when I remove the if statement, but I want the if statement to select ships for my pygame menu. Does anyone know how to solve the bug or have an idea about some other way to select ships?