 In July 2014, ASA Târgu Mureș announced they reached an agreement to sign Constantin for a season.Constantin made his international debut on 27 May 2004 in a match against Ireland.On 25 March 2008 he was decorated by the president of Romania, Traian Băsescu for the results on Qualifying to EURO 2008 and qualification to UEFA Euro 2008 Group C with Medalia "Meritul Sportiv" — (The Medal "The Sportive Merit") class III.