Helsingborg stunned the footballing world when they defeated Italian giants Inter Milan 1-0 on aggregate to become the first Swedish club to reach the Champions League group stages.
 Unfortunately, Helsingborg's luck ran out in the group stage and they were soundly beaten in their first three matches; they recovered to chalk up respectable draws against Paris Saint-Germain and that season's European champions, Bayern Munich, but finished bottom of their group and failed to even drop down into the UEFA Cup.
This is a list of matches of FC Shakhtar Donetsk in Europe.
 Shakhtar Donetsk participates in European competitions since 1976 after playing its first against Berliner FC Dynamo in the 1976–77 UEFA Cup.
 Since 1997, however, the club continuously participates on annual basis with variable successes, while also taking part in UEFA Champions League competition since 2000.
 Shakhtar's first qualification to a group stage in a European competition took place in the 2000–01 UEFA Champions League, when Shakhtar Donetsk played against Arsenal, Lazio and Sparta Prague in Group B.
 While being a constant presence in Champions League group stages, Shakhtar have only reached UEFA Cup/UEFA Europa League group stages twice (2005–06 and 2009–10).
The 2016 season was Helsingin Jalkapalloklubi's 108th competitive season.
 HJK is the most successful football club in Finland in terms of titles, with 27 Finnish Championships, 12 Finnish Cup titles, 5 Finnish League Cup titles, one appearance in the UEFA Champions League group stages and one appearance in the UEFA Europa League group stages.
Ciarán Kilduff (born 29 September 1988) is an Irish footballer who plays as a striker for the Jacksonville Armada in the North American Soccer League.
 He has played for six clubs in the League of Ireland throughout his career and appeared 16 times in European competition, playing in the Europa League group stages in two separate seasons.
 The first occasion was with Shamrock Rovers when they became the first Irish side to reach the group stage of the Europa League in 2011, and he was also part of the Dundalk team that qualified for the Europa League group stages after becoming the first Irish club to reach the play-off round of the Champions League in 2016.
Luís Filipe Madeira Caeiro Figo, (] ; born 4 November 1972) is a retired Portuguese footballer.
 He played as a midfielder for Sporting CP, Barcelona, Real Madrid and Internazionale before retiring on 31 May 2009.
 He won 127 caps for the Portugal national team, a record at the time but later broken by Cristiano Ronaldo.
Luis Suárez Miramontes (] ; born 2 May 1935), also known by the diminutive Luisito, is a Spanish former footballer and manager.
 He played as a midfielder for Deportivo de La Coruña, CD España Industrial, FC Barcelona, Inter Milan, Sampdoria and Spain.
 Suárez is regarded as one of Spain's greatest players; he was noted for his elegant, fluid, graceful style of play.
 Nicknamed "El Arquitecto" (The Architect) he was noted for his perceptive passing and explosive shot and in 1960 he became the only Spanish-born player to be voted Ballon d'Or.
 In 1964 he helped Spain win the European Championship.
 Suarez originally achieved prominence as a creative inside forward or attacking midfielder for the great Barcelona team of the 1950s before he joined Inter Milan where he reached his prime as deep lying playmaker for the legendary "Grande Inter" team of the 1960s.
 He played a pivotal role in the success Herrera's Inter Milan side, and was one of the primary creative forces in the squad, due to his ball skills, vision, and passing range.
 He retired as a player in 1973, after three seasons at Sampdoria.
The 2005–06 Serie A season opened with success in the Supercoppa Italiana, beating Juventus 1–0 in extra time with a goal scored by Verón.
 During the Champions League group stage, the side managed to have a line-up of 11 foreign players on the pitch: the only european was Luís Figo, playing the second time.
 Despite a good first half (also including a 3–2 win in derby, that lacked since 2002) Inter did not have a great second half, and knocked out in the Champions League by Villareal.
The 2013–14 PSV Eindhoven season saw PSV competing in the Eredivisie, KNVB Cup, UEFA Champions League and the UEFA Europa League.
 PSV finished the season in 4th place in the Eredivisie, qualifying for the UEFA Europa League again, where knocked out of the KNVB Cup by Roda JC in the Third Round.
 In Europe PSV where knocked out of the Champions League at the Play-off Round by A.C. Milan, ending up in the Europa League group stages, from which they did not progress.
The 2017 season is Helsingin Jalkapalloklubi's 109th competitive season.
 HJK are Finlands most successful football club in terms of titles, with 27 Finnish Championships, 12 Finnish Cup titles, 5 Finnish League Cup titles, one appearance in the UEFA Champions League group stages and one appearance in the UEFA Europa League group stages.
The 2015 season was Helsingin Jalkapalloklubi's 107th competitive season.
 HJK is the most successful football club in Finland with 27 Finnish Championships, 12 Finnish Cup titles, 5 Finnish League Cup titles, one appearance in the UEFA Champions League group stages and one appearance in the UEFA Europa League group stages.

Question: The 2005–06 Serie A season for Inter Milan had a single European player on the roster during the Champions League group stages, that of the retired footballer of what nationality? 
Answer: Portuguese