Doctors tried to resuscitate Alex, but they said he had severe brain swelling.
Police said he had fatal head and stomach injuries and he was covered with bruises on his neck and body, The Telegraph reported. Alex died two days after the beating, the Independent reported.
Iheanacho was sentenced to life in jail with a minimum of 18 years.
The judge who presided over the sentencing said that Iheanacho has a "deeply entrenched character flaw" that made him lose his temper, The Telegraph reported.