Sanches' performances then attracted German side Bayern Munich, who signed him in July 2016 for an initial €35 million, the highest fee at the time for a Portuguese player playing in the Primeira Liga.

His performances fell during his first season with the club, leading him to be loaned to Premier League side Swansea City in August 2017.

[12] He convinced Benfica to take him after training with them for 15 minutes, but he initially had reservations about travelling to their academy in Seixal every day, on the other side of the Tagus river.

[13] He was sent off twice with straight red cards in the second half of the season: as a substitute in a 3–2 home win over Porto B on 11 January 2015,[14] and a starter in a 1–1 draw at Santa Clara on 7 March.

[21] On 25 November, he made his first appearance in the starting line-up, playing 90 minutes in a 2–2 away draw with Astana in the UEFA Champions League group stage.

[23] Aged 18, on 4 December, he scored his first goal for Benfica, beating Académica's goalkeeper Trigueira with a 30-metre strike and sealing the 3–0 league win.

[28] On 8 May, Sanches was sent off for a second yellow card in the first half of a 2–0 win at Marítimo,[29] missing Benfica's last league match in which they retained their title at the expense of city rivals Sporting CP with victory over Nacional.

[30] In his last match, the 2016 Taça da Liga Final in Coimbra on 20 May, Benfica won the league cup 6–2 against Marítimo.

[37] The initial fee was the fourth-highest paid in Bayern Munich's history, after those for Javi Martínez, Mario Götze and Arturo Vidal.

[37] Sanches had been tracked extensively by Manchester United before joining Bayern, and their Portuguese former player Nani said they would regret not completing a transfer for him.

[38] After recovering from a thigh injury, Sanches made his debut on 9 September, starting in a 2–0 win at Schalke 04 in place of Arturo Vidal.

Although he made errors in his 71 minutes before being replaced by Joshua Kimmich, he was given reassurance by captain Phillip Lahm and goalkeeper Manuel Neuer, with the former saying, "He's a very, very good player, otherwise he wouldn't be here.

[41] On 31 August 2017, Sanches joined Premier League club Swansea City on a one-year loan lasting until 30 June 2018.

[46] On 29 November, manager Paul Clement substituted Sanches at half-time in a 1–0 loss to Chelsea after he had played a pass into the advertising boards on the side of the pitch, believing it to be a teammate.

[47] Sanches suffered hamstring injuries in two consecutive FA Cup matches in January 2018, and new manager Carlos Carvalhal allowed him to go home so the warmer weather could aid his rehabilitation.

[60] Initially, Lille's manager Christophe Galtier used Sanches in a variety of positions, being limited to substitute appearances, before playing a match as a starter for the club on 30 November in a 1–0 against Dijon, operating on the left of the midfield.

[69] On 16 August 2023, Sanches signed for Serie A club Roma on a season-long loan with an option to make the move permanent that would become obligatory under certain conditions.

[75] He represented Portugal in the 2014 UEFA European Under-17 Championship, helping them reach the semi-finals, where they lost to eventual winners, England.

[78] He debuted for Portugal as a 76th-minute substitute for William Carvalho in the 0–1 loss against Bulgaria in Leiria, and shortly after he was greeted by a fan who invaded the pitch.

[79] Sanches was called up for UEFA Euro 2016, making him the youngest Portuguese to be selected for an international competition, breaking a record held by Cristiano Ronaldo for 12 years.

[80] Sanches made his competitive debut on 14 June in the team's opening match against Iceland in Saint-Étienne, replacing João Moutinho for the final 19 minutes of a 1–1 draw.

[12] Five days later in the quarter-finals against Poland, Sanches overtook Ronaldo's record as the youngest Portuguese to start in a major tournament.

[83] After a one-two with Nani, Sanches shot from outside the box and equalised in the first half to become the youngest player to score in a knockout match at a UEFA European Championship and the third-youngest overall.

[85] Following the match, teammates Nani and José Fonte praised Sanches' stamina, confidence and desire to learn from his elders.

[92] Following the bad performances of teammates Danilo Pereira and William Carvalho in a 4–2 loss against Germany, Sanches emerged as one of the crucial players for Portugal in the competition, with coach Fernando Santos giving him a chance in Portugal's final two games at the tournament, impressing in a 2–2 draw with France in their final group stage match.

[100] During Euro 2016, former Benfica and Netherlands player Pierre van Hooijdonk also drew comparison with Seedorf, saying "the way [they] play is the same, the intensity also".

[101] During his time with Lille, under manager Christophe Galtier, Sanches was deployed in a double pivot alongside Benjamin André in a 4-2-3-1 formation, or as an inverted midfielder, operating in an attacking role on the right-wing.

[7] According to Goal.com writer Miles Chambers, the accusations against Sanches stem from conscious or unconscious racial stereotyping, based on historical occasions in which players from the African continent have lied about their age, although he was born in Portugal.