June 18 (UPI) -- Croatian striker Nikola Kalinic is being sent home from the World Cup after he refused to come on as a substitute against Nigeria, citing a back injury.
The Croatian Football Federation announced the move on Monday. Croatia beat Nigeria 2-0 in a Group D bout Saturday in Kaliningrad, Russia.
"During the Nigeria encounter, Kalinić was warming up and was supposed to come on in the second half," Croatian coach Zlatko Dalic said Monday in a release from the CFF.
"However, he then stated that he wasn't ready to come on due to a back issue. The same thing happened during the Brazil friendly in England, as well as before the practice session on Sunday. I have calmly accepted that, and since I need my players fit and ready to play, I have made this decision."
Kalinic, 30, has 41 appearances and 15 goals for Croatia. The Croatians battle Argentina on Thursday before wrapping up their Group D slate on June 26 against Iceland.
The Croatian striker had six goals in 41 games last season for Milan. He made his senior team debut for Croatia in 2008. Kalinic previously played for Hajduk Split, Pula, Sibenik, Blackburn Rovers, Dnipro Dnipropetrovsk and Fiorentina before joining Milan on loan in 2017.