Chelsea striker Romelu Lukaku is among the big names to have been dropped from the Belgium squad as Roberto Martinez focuses on youth. Lukaku joins the likes of Dries Mertens, Eden Hazard and Kevin De Bruyne, with Martinez opting to leave out players with more than 50 caps ahead of his team’s friendlies with the Republic of Ireland and Burkina Faso later this month.Martinez is using the two matches to prepare for the World Cup in Qatar where top-ranked Belgium are expected to be among the contenders. Youri Tielemans is the most experienced player selected with 47 caps while Jeremy Doku returns…