A deep-lying playmaker capable of directing gameplay through short and calm passes and his singular reading of the game, he is widely regarded as the greatest defensive midfielder of all time.

[18] On 27 May 2009, having been regularly played as he competed for the spot with internationals Seydou Keita and Yaya Touré, he also featured in Barcelona's starting eleven in the Champions League final, a 2–0 win over Manchester United in Rome; with that victory, Carles Busquets and Sergio Busquets became only the third father-and-son combo to both have won Europe's top club competition playing for the same team, joining Cesare Maldini and Paolo Maldini (won it with A.C. Milan) and Manuel Sanchís and Manolo Sanchís (Real Madrid).

In the second leg of the Champions League semi-final 1–0 victory (and an eventual 2–3 aggregate defeat) against Inter Milan at Camp Nou on 28 April 2010, he went down to the ground after Thiago Motta had raised his arm and appeared to push Busquets directly in the face.

[22] As a result of this action, the former was shown a red card and dismissed for violent conduct, whilst the latter was subsequently criticised by both Motta and the media for apparently feigning injury.

[30] Busquets scored a rare goal on 24 April 2012 – only his sixth official one in four years – netting from an easy tap-in after an Isaac Cuenca cross to make it 1–0 for the hosts in the second leg of the Champions League semi-finals against Chelsea.

[33] Busquets started on 6 June in the 2015 Champions League final, as the team won their fifth accolade in the competition by beating Juventus 3–1 at Berlin's Olympiastadion.

[36] Busquets opened the scoring in a 3–0 win against Las Palmas on 1 October 2017, with the match being played behind closed doors at the Camp Nou due to the ongoing Catalan independence referendum.

[38] On 24 November 2018 he played his 500th game for Barcelona away to Atlético Madrid,[39] and he made his 100th Champions League appearance on 11 December, in a 1–1 group stage home draw against Tottenham Hotspur.

[42] On 12 January 2023, Busquets made his 700th appearance for Barcelona in his team's penalty shoot-out victory after a 2–2 draw against Real Betis at the King Fahd International Stadium in 2023 Supercopa de España semi-final.

[44] On 2 March, in the next El Clásico match, Busquets broke both records as Barcelona won 0–1 in the first leg of the 2023 Copa del Rey semi-final.

He won his first title with the club on 20 August 2023, helping Inter Miami beat Nashville SC in the 2023 Leagues Cup final.

[55] He was named as a substitute for a 2010 FIFA World Cup qualifier against Turkey on 28 March 2009,[56] making his debut in the return match on 1 April, playing 16 minutes in a 2–1 win in Istanbul after replacing David Silva.

Busquets was selected by manager Vicente del Bosque for the 2010 World Cup in the same country, assuming the holding midfielder role naturalized Brazilian Marcos Senna had previously occupied in the conquest of UEFA Euro 2008.

[71] He tested positive for COVID-19 eight days before Spain's first game, causing the entire squad to withdraw from their final warm-up match against Lithuania.

[76] In the UEFA Nations League final against France on 10 October 2021, Busquets set-up Mikel Oyarzabal who scored the opening goal of the match, although Spain ultimately suffered a 2–1 defeat.

[84] Busquets is known for redefining the deep-lying midfield position by focusing on football intelligence, precision passing, and a ‘genius’ ability to read the game rather than overwhelming strength or physicality.

[85] A hard-working player, he excels at intercepting loose balls and breaking down opposition plays due to his positional sense, defensive attributes, tackling, tactical intelligence, and ability to read the game, despite his lack of pace.

[12][84][86][87][88] Due to his vision, ball control, physical prowess, technical skills, calm composure on the ball, and accurate passing ability, he rarely relinquishes possession, and alongside his former Barcelona midfield teammates, such as Iniesta, Xavi and Ivan Rakitić, he has also played an important creative role in setting his team's tempo in midfield as a deep-lying playmaker through his short passing game.

[86][89][90][91][92][93][94] His role has also been likened to that of a metodista ("centre-half," in Italian football jargon), due to his ability to dictate play in midfield as well as assist his team defensively.

"[97] The latter's height also allows him to be effective in the air, and enables him to advance into more offensive positions on occasion, providing an additional attacking outlet for his team.