Nikola Kalinic, Croatia’s striker has been reportedly sent back home after refusing to come on as a substitute during their 2-0 victory over Nigeria in their first World Cup clash on Saturday. 

Kalinic who was left on the bench was ordered to enter by boss Zlatko Dalic in the final minutes of the Group D clash in Kaliningrad. But according to reports in Croatia, the striker declined his manager';s orders, citing a problem with his back.

The Croatia boss was then forced to turn to Marko Pjaca, a wide player, to come on in place of forward Mario Mandzukic.

Speaking in the wake of Saturday';s win, Dalic told reporters that the team had finished the game without injuries but ';with a problem';. 

During Croatia training ahead of Argentina clash at their Saint Petersburg base on Sunday, there was no sign of Kalinic, Daily Mail confirmed

According to the report, the AC Milan forward is believed to be taking the first flight back home from Russia this week, leaving Croatia with Mandzukic the only out-and-out striker available in their squad.

However, the Croatian Football Association has not yet confirmed Kalinic';s expulsion but Dalic will address the issue at a press conference later today.