sentences:  O'Donnell played youth football for Newcastle in County Galway before joining Arsenal as a trainee in the summer of 2002 after completing his Junior Certificate exams.He signed a professional contract at the club in January 2003 but left again in July 2005 without making an appearance for the first team.While he credits the coaching he received during this time with giving him greater confidence on the ball, he has expressed regret at moving to Arsenal at such a young age, feeling that if given the choice again he would have stayed at home, completed his Leaving Certificate exams and joined a team in the League of Ireland.