Slovakia’s long-serving captain and former Napoli attacking star Marek Hamsik said Monday he would step down from international duty aged 34. “It wasn’t easy, I have thought long about it but after 15 years I have decided to close a meaningful and wonderful part of my football career,” he wrote on social media. Hamsik said he was “very proud” and “downright moved” to have been a part of Slovakia’s major successes which included World Cup participation in 2010 and reaching both Euro 2016 and Euro 2020. National coach Stefan Tarkovic said it was the end of an era for the team as Hamsik’s long-se…