The Republic of Ireland have dropped four places to 62nd in the FIFA world rankings after their back-to-back UEFA Nations League losses to England and Greece at Aviva Stadium.Heimir Hallgrimsson endured a tough start to his reign as head coach as the the Boys in Green were outclassed by the English in a 2-0 defeat before Greece rubbed salt into the wounds with a 2-0 win three days later.It's a long way from the halcyon days of 1992 when Jack Charlton's giantkillers were ranked as high as sixth.Ireland's lowest ever ranking position came in June 2014, when they sank to 70th.In October, Hallgrimsson's charges face away trips to Greece (48th in the rankings) and Finland (64th).Argentina remain the top-ranked team in the world ahead of France, European champions Spain, England and Brazil.Belgium, the Netherlands, Portugal, Colombia and Italy make up the top 10.