The roots of Castaignos' family are located in Les Landes, one hundred kilometers below Bordeaux in the south-west of France. There, Castaignos' father, the French-born Jean Luc Castaignos, met Castaignos' mother who is of Cape Verdean descent and holder of an Italian passport. In October 1990, two years before Luc's birth, the family moved to the Netherlands.
Castaignos started his youth career at the local Schiedam club Excelsior '20. The youngster lived close to Sportpark Thurlede, the home ground of the Catholic club. His former Excelsior '20 coach, Paul Benschop, was soon convinced by Castaignos' quality: "Everyone could see how much potential he had. Whenever we conceded a goal, Luc would take care of business." At the age of 13, Castaignos participated on regional club Spartaan '20's opening day. The club from Rotterdam, youth partner of Feyenoord, saw plenty of potential in the youngster and invited him to join. Castaignos only played one season for Spartaan '20. When various professional clubs showed their interest, Spartaan '20 warned Feyenoord.
At the age of 14, Castaignos joined the Feyenoord Academy in the summer of 2007. On 30 October 2008, Castaignos signed his first professional contract with Feyenoord keeping him at De Kuip until summer 2011 with an option for another 2 seasons.
After a successful performance with the Netherlands U17 at the 2009 UEFA European Under-17 Football Championship, a clutch of sides were linked to the Dutch youngster. Besides Arsenal, also Liverpool, Manchester United, Real Madrid, Internazionale, Bayern Munich and TSG 1899 Hoffenheim showed their interest in the Feyenoord top scorer. However, on 22 July 2009, Castaignos crushed all rumours and told Feyenoord manager Mario Been and technical advisor Leo Beenhakker he wanted to stay in Rotterdam.
On 21 June 2009, Been announced he invited Castaignos to train with the first team squad a few times a week. On 13 August 2009, Castaignos trained with the first team squad for the first time. Castaignos made his official debut in Feyenoord's first team on 24 September 2009 replacing Leroy Fer in the 72nd minute in the KNVB Cup away match against Harkemase Boys (0â€“5). Five months later after making his first team debut and being on the unused bench, Castaignos made his debut, coming on for Jon Dahl Tomasson in a 3â€“2 loss against Groningen on 28 February 2010. That season later on, he would make two more appearance and the club would finish fourth place.
The 2010-2011 campaign proved to be Castaignos' breakout season, stemming from squad rotation and losses in the transfer market. However, for the club, the club finished 10th place in the league, missing out on the Europa League in the process. He scored his first career goal on 28 August 2010 in a 4â€“0 win over Vitesse. Castaignos made his Europa League debut in a 1â€“0 win over Gent, coming on as a substitute. On 22 February 2011, he scored his first brace of his career, in a 2â€“2 draw against ADO Den Haag. His goal on the season's final day against N.E.C. would prove to be his last at the club. When it was all said and done, Castaignos led the team in scoring with 15 goals.
After rampant speculation during the January transfer window linking Castaignos with Italian giants Inter, On 4 March 2011, Feyenoord announced that they had agreed to terms with Internazionale, selling Castaignos for a fee believed to be around â‚¬3 Million upon the completions of the 2010â€“2011 season.
He featured throughout preseason, most notably scoring the opening goal in a friendly against Celtic on 30 July 2011. He made his competitive debut for Inter in a Supercoppa Italiana, coming on for Joel Obi in a 2â€“1 loss against Milan, where he played in front of 70,000 people at Beijing National Stadium, Beijing China PR.
He made his full league debut in a 3â€“1 loss against Novara. Castaignos scored his first goal in Serie A in an away match to Siena on 27 November 2011, latching on to Thiago Mottaâ€™s through ball before firing low past Brkic, which proved to be the gamewinner.
On 17 February 2012 in a 3â€“0 loss against Bologna, Castaignos was involved in alteration with Andrea Raggi after Castaignos spat on Raggi in the 85th minutes. After Serie A officials reviewed footage of the incident, he was subsequently banned for three matches. His actions caused Inter to immediately move him into a reserve role, scoring twice in three appearances for the reserve squad. In April 2012, Castaignos suffered an hamstring injury, missing out for the rest of the season during a match against Calcio Padova.
At the end of the season, Castaignos announced his intention to leave Inter in favor of a 'big club'. Castaignos was linked with Liverpool. Liverpool tried and failed to sign him in the January transfer window. Tottenham Hotspur also displayed interest, as well as West Ham United, Everton, and even including his former club Feyenoord.
On 28 July 2012, Castaignos made his return to the Dutch Eredivisie when Twente agreed to terms with Internazionale for 6 million euros. Castaignos was seen as the replacement for the former Twente striker Luuk de Jong, who had been sold to Borussia Monchengladbach. On 12 August 2012, he made his debut, coming on for Dmitri Bulykin in the second half, in a 4â€“1 win over Groningen. On 26 August 2012, he scored his first goal and set up a goal for Dmitri Bulykin in a 3â€“1 win over NEC Nijmegen.As of match played 17 August 2015.
1 Includes UEFA Champions League and UEFA Europa League matches.
At the age of 15, Castaignos made his first international appearance on 18 September 2008 in a friendly match of the Netherlands U17 against Spain U17 (0â€“0).
Castaignos' international fame started to rise after the 2009 UEFA European Under-17 Football Championship in Germany. The Dutch team, aided by a strong contingent of seven Feyenoord players in the squad, finished second after losing the final to Germany U17 in extra-time (2â€“1). Castaignos was considered one of the key players in the team, picked up the tournament's top scorer award alongside Lennart Thy and was mentioned in the team of the tournament. With 13 goals, Castaignos is the all-time top scorer of the Netherlands U17.
Castaignos playing style led the media to compare him to Thierry Henry.Netherlands:
UEFA European Under-17 Football Championship: 2009 (runner-up)
UEFA European Under-17 Football Championship: Top Scorer 2009
All-time Netherlands U-17 Top Scorer