Salah, Neymar, Messi, messy, messy: World Cup stars stifled

Argentina's Lionel Messi, right, leaves the pitch as Croatia's Sime Vrsaljko celebrates his side's 3-0 victory at the end of the group D match between Argentina and Croatia at the 2018 soccer World Cup in Nizhny Novgorod Stadium in Novgorod, Russia, Thursday, June 21, 2018. (AP Photo/Pavel Golovkin)

SARANSK, Russia — With nagging injuries, heavy marking from opponents and some simply uninspired play, the top stars of the 2018 World Cup have struggled to deliver on the impossible expectations they carried into the tournament, with one prominent Portuguese exception.