Arsenal are plotting a summer move for Atletico Madrid defender Toby Alderweireld, [football] direct news understands.A source close to the Emirates Stadium told FDN that boss Arsene Wenger wants more competition for places at the heart of his backline and hopes to land the towering centre-half for a relatively modest fee, having seen him struggle to settle in Spain.The Belgium international has made no secret of his unhappiness at the La Liga title challengers, and at the turn of the year he told Dutch television network Sport-1 that he was open to an emotional return to Amsterdam with former club Ajax.Arsenal club captain Thomas Vermaelen is widely-expected to leave at the end of the season, having fallen down the pecking order in north London, and Alderweireld is viewed as a natural replacement.The 24-year-old joined Atletico from Ajax last summer for 6.1million but has often been used as a substitute.Watch Arsenal v Man City Saturday or Liverpool v Tottenham Hotspur, Sunday. 24 hour Sky Sports day pass for only 9.99. No contract.