Here are the things to know about the forward who returns to the Super Eagles after 19 months.
Born in Benin City, Nigeria, on January 7, 1996, Isaac Great Success Ajayi is 22-years-old.
Isaac Success started his youth career with BJ Foundation in Nigeria before he moved to Spanish La Liga side Granada in 2014 after he agreed on a deal with Italian Serie A Udinese but could not get a work permit.
He spent two seasons with Granada B side where he scored nine goals in 20 appearances.
He gained promotion to the first team and in 2014 at just 18-year-old he became the youngest player ever to appear in a La Liga match for Granada.
He made a total of 49 appearances and contributed seven goals for the Granada first team before he moved to English Premier League side Watford.
He spent one and a half season with Watford battling with injuries and inconsistencies before he returned to Spain on loan with Malaga.
He could however not save them from relegation and returned to Watford for the 2018/19 season.
Isaac Success was born in Nigeria and is represented the country at various levels.
He the vice-captain for the victorious Golden Eaglets team that won the 2013 Africa Cup of Nations (AFCON)and FIFA U-17 World Cup titles.
The achievement played a part as Success moved to Europe and returned to wear the green and white for the Flying Eagles at the FIFA U-20 World Cup as they crashed out in the second round.
Success was invited for the 2018 FIFA World Cup qualification game against Zambia and made his only appearance for the senior national team in the Super Eagles draw with Senegal in an international friendly encounter played in 2017 at The Hive Stadium in London.
At 22-year-old, Success is still very much in his development phase as a footballer and has battled with injury for most of his career.
He is a right-footed forward that can play as a lone striker or up top supporting the target man.
His versatility and pace has also seen him shunted to the flanks more on the left where he can cut in.
He has scored two goals in the Carabao Cup games against Tottenham Hotspur and Reading and is getting more suited to a central position.
He is having a better season under Premier League Manager of the Month winner Javi Gracia.
The striker is however behind Watford captain Troy Deeney and Andre Gray in the pecking order.
He is expected to challenge Odion Ighalo and Leicester City forward Kelechi Iheanacho for the starting sport in the Super Eagles.
Isaac Success is yet to win any individual award both at international level and for at his previous club sides on loan.
His only achievement was with the Nigerian U17 team Golden Eaglets where he was part of the team that won the FIFA U-17 World Cup in 2013.