Nnamdi Oduamadi Chidiebere was born on 17 October 1990 in Lagos State of Nigeria. He is also known by his shirt name Odu, started playing football at the local Pepsi Football Academy at the age of 7. He left his home country in 2008 to join Milan, although he was officially signed only in January 2009 due to bureaucratic issues. Oduamadi spent two seasons in the club’s youth system and was a member of the under-20 side who won the Coppa Italia Primavera in 2010, 25 years after the team’s last success in the competition.
For the 2012–13 season, Oduamadi joined Serie B side Varese on another loan deal. At the start of the 2013–14 campaign, He moved to Serie B club Brescia, once again on loan. On 31 January 2014, Nnamdi rejoined Varese, making his second loan spell. Looking at his international level, Oduamadi was first capped by Nigeria U-17, when he was at the Pepsi Football Academy. He went on to be called up by Nigeria U-20 to take part in the 2009 FIFA U-20 World Cup, but eventually was cut from the final squad due to an hamstring injury.
Oduamadi made his full international debut for Nigeria against Kenya, on 29 March 2011, featuring as a second-half substitute. Two years later, he made his second appearance against Kenya in a 2014 World Cup qualifying match, where he scored the equalizing goal in the 94th minute to level the score. Oduamadi was selected for Nigeria’s squad at the 2013 FIFA Confederations Cup, in which he scored three goals against Tahiti in their opening match.