Right way to add a Doctrine2 relation

OneToManyFixture2.php

<?php

namespace Acme\DemoBundle\DataFixtures\ORM;

use Doctrine\Common\Persistence\ObjectManager;
use Doctrine\Common\DataFixtures\FixtureInterface;

use Acme\DemoBundle\Entity\Team;
use Acme\DemoBundle\Entity\Player;

class LoadDemoDataOI implements FixtureInterface
{
    public function load(ObjectManager $manager)
    {
        
        $players_source = array(
            array("name" => "Giuseppe Giannini"),
            array("name" => "Marco Van Basten"),
            array("name" => "George Best")            
        );
        
        $_team = new Team();
        $_team->setName("Dream team B");
        $manager->persist($_team);
        
        foreach ($players_source as $player_data) {
            
            $_player = new Player();
            $_player->setName($player_data['name']);
            $_player->setPlayfor($_team); # This is a change on the owning side in our relation
            $manager->persist($_player);
            
        }
        
        $manager->flush();
            
    }
            
}