Career
He is the youngest ever player to have played for the club, making his senior debut at the age of 16 years and 6 days. Liverpool
= Academy Liverpool signed Sinclair as a 14-year-old from the West Bromwich Albion youth academy in the summer of 2011 after becoming a free agent. The Liverpool coaching staff compared him to Raheem Sterling.
He spent most of the 2011-2012 season with the Under-16s before coach Mike Marsh gave him a run of four games with the Under 18s at the end of the season.
He impressed greatly in those games, though he failed to find the back of the Netto. On 14 July 2012, Sinclair came off the bench to score a hat trick against Exeter City in an Under-18s pre-season friendly.
In all, Sinclair netted eight goals in the six Under-18s pre-season friendly games in the run up to the 2012-2013 Academy Under 18s season. He went on to score his first competitive goals for the Under-18s on 25 August 2012, hitting a brace in a 3–3 draw with Crystal Palace.
= Reserves and first-team debut Sinclair started the match and impressed throughout, winning a penalty that Krisztián Adorján converted and going close himself on more than one occasion.
His fine form brought him to the attention of first team coach Brendan Rodgers, who called Sinclair up to the first team for the League Cup third round tie away to West Bromwich Albion on 26 September 2012. Foreign the remainder of 2012-2013 season Sinclair continued to play for Liverpool U18s. The 2013-2014 season saw Sinclair make limited progress with the player injured for large spells of the season.
Up until the beginning of March in the 2014-2015 season, Sinclair scored 22 goals for Liverpool youth teams at various levels including 6 goals in 7 Union of European Football Associations Youth League games as well as impressive finishes against Manchester United U21, against Víctor Valdés in goal, and a solo effort against Chelsea U21.
His good form was rewarded by inclusion in the first team squad for a Europa League tie against Beşiktaş J.K. in February. On 16 March 2015, Sinclair was loaned to Championship side Wigan Athletic, where he linked up with academy teammate Sheyi Ojo.
The next day, he made his Football League debut in his only Wigan appearance, replacing Marc-Antoine Fortuné for the final eight minutes of a 0–2 loss to Watford at the DW Stadium. On returning to Liverpool, Sinclair made his Premier League debut on 10 May when he came on as a 68th-minute substitute for Rickie Lambert in a 1–1 draw at champions Chelsea.
Ten days later he confirmed that he would leave Liverpool at the end of the season, eyeing a move to Spain.
He made his England under-16 debut on 27 October 2011, and scored as England beat Wales 4–0 in the 2011 Victory Shield. He also scored twice in the 2012 Montaigu Tournament, earning England wins against host nation France, and Morocco. He is currently in the England-under 17 squad.
On 2 October, he was named in the 18-man squad for the 2013 Union of European Football Associations European U17 Championship qualification matches in Estonia.