Born in Edo, Emmanuel started his playing career in his native Nigeria for My People FC, a Nigerian football Academy based in the Nigerian capital of Lagos and which was ran by the Synagogue Church of Nations. In 2009 Emmanuel joined Swedish club Bodens BK where he stayed for only a few months as FIFA rules stated that he had to be 18-years old to make an international transfer. Then in 2010, after his award-winning performance at the 2009 FIFA U-17 World Cup, it was reported that Emmanuel had trials at both Chelsea and Tottenham Hotspur of the English Premier League. While at Tottenham Emmanuel was even offered an extended stay. However in 2011, after trialing at several clubs in Europe, Emmanuel signed for Italian Serie A side S.S. Lazio where he was immediately put into their Primavera side. Then in 2012 it was announced that Emmanuel had signed for U.S. Salernitana 1919 of the Lega Pro Seconda Divisione on a co-owned basis from Lazio and on 9 September 2012 Emmanuel made his only appearance for the 4th tier Italian side against Chiete Calcio in which he came on in the 58th minute for Christian Chirieletti as Salernitana suffered a 4–1 defeat that day.
Then on 16 February 2013 it was announced that Emmanuel had signed with Swiss Challenge League side FC Biel-Bienne on loan for the rest of the season. Emmanuel then made his debut for the club on 16 March 2013 against Wohlen in which he came on in the 72nd minute for Ramon Egli as Biel-Bienne lost the match 1–0.
On 12 May 2013 Emmanuel scored his first professional goals in a league match against FC Wohlen in which he scored a hat-trick to lead Biel-Bienne to a 7–0 victory. He then scored two more goals for Biel-Bienne on 30 May 2013 against FC Winterthur as the club 2–2.
Emmanuel rose the prominence during the 2009 FIFA U-17 World Cup which was hosted in his home country Nigeria. Emmanuel finished the tournament by winning the Golden Ball with 5 goals as he helped Nigeria to a runners-up finish behind Switzerland.