Career
He also represents the Philippines at international level As a youngster, Hartmann had stints with Portsmouth and then at Swindon Town where he was eventually released at the end of the 2009-2010 season. He then joined Wessex Football League side Blackfield & Langley.
After his stint with Blackfield & Langley, he moved to the Philippines where he would join Manila Nomads.
In the 2010-2011 United Football League mid-season transfer window, he joined Loyola Meralco Sparks and then scored his first goal in a 2–1 defeat to the Philippine Air Force. In September 2011, he joined the national team training pool and was named in the final 20-man squad for the 2011 Long Teng Cup and the provisional Philippines under-23 squad for the 2011 Southeast Asian Games.
In the Long Teng Cup, he made his full international debut in the 3–3 draw against Hong Kong. He made his first appearance for the under-23 national team in the 3–1 loss against Vietnam in the opening match of the 2011 Southeast Asian Games.
He scored his first and second International Goal during the 2014 Philippine Peace Cup over Chinese Taipei.
On 12 October 2014 Hartmann scored a super hat-trick during the first half in a 5-0 victory over Papua New Guinea. International goals Scores and results list the Philippines" goal tally first. Hartmann became the first coach of the women"s team of the Manila Nomads known as the Nomads StretchMarks.