Nigeria have named four Premier League players in their Olympics squad.
Arsenal starlet Alex Iwobi has been named in the 35-man contingent, along with Man City's Kelechi Iheanacho, Chelsea midfielder John Obi Mikel and Watford striker Odion Ighalo.
However, they face a battle with the clubs to release the players as City are adamant Iheanacho will not travel to Brazil, says the Mirror.
Boss Samson Siasa has also indicated Watford will not release Ighalo while there are doubts over Mikel's ability.
The competition runs into August with players set to miss the first month of the Premier League season.