In January 2010, he joined the Belgian team RSC Anderlecht on a six-month loan-deal.
On 1 August 2012, Martínez joined MLS club Seattle Sounders FC on loan from Real España. His first training session in Seattle was 17 August 2012. He participated in a reserve league match with the Sounders on 19 August 2012 in a 3–2 win over the Los Angeles Galaxy reserves. His first goal for the Sounders won the Western Conference semi-final match against Real Salt Lake on 8 November 2012.
Martínez was a part of the Honduras U-23 team that competed in the 2008 Summer Olympics in Beijing. He was the youngest player in the squad, being only 19 years old. On 4 September 2010, Martínez made his debut for the Honduras National Team in a match against El Salvador, where Honduras won 4–3 via penalty shootout due to a 2–2 tie in regular time. He assisted the first goal for Honduras, thus helping his team to the Copa Independencia.