 He made his senior debut 2 years later as a substitute in a 3–1 defeat of Dundee United on 23 December 2000 and, after a further two substitute appearances, was loaned to Cowdenbeath in March to further aid his development.In 2001–02 Simmons blossomed into a first team regular.He scored his first senior goal against Rangers in September to earn Hearts a 2–2 draw and netted a further 4 times during a season in which he also earned Scotland U21 recognition.