Xu started his football career when he joined Tianjin Teda's youth academy in 2006. After switching to Shanghai Shenhua's youth academy, he then transferred to La Liga side Atlético Madrid's youth academy in 2010. On 11 May 2013, Xu was promoted to Atlético Madrid B's squad and made his debut for the club on 12 May 2013 in a 1–0 loss against CD Marino, coming on as a substitute for Vicente Romero in the 66th minute.[1][2] He made his debut for Atlético Madrid C on 25 August 2013 in a 2–2 draw against AD Parla, coming on as a substitute for Samuel Villa in the 71st minute.[3]
Guanzhou Evergrande
On 25 December 2015, Xu transferred to Chinese Super League side Guangzhou Evergrande for a fee of €4.3 million.[4][5] He made his debut for the club on 1 April 2016 in a 2–0 win against Guangzhou R&F, coming on as a substitute for Huang Bowen in the 71st minute.[6] On 1 April 2017, Xu suffered a ligament rupture in his left ankle in a 3–2 win against Shanghai SIPG.[7] In July 2018, Xu was reportedly about to be loaned to China League One side Wuhan Zall for a half season.[8] However, the deal couldn't be completed due to Guangzhou Evergrande and Wuhan Zall falling out over a dispute about Yang Chaosheng.[9]
Shandong Taishan
On 12 April 2021, Xu joined fellow Chinese Super League club Shandong Taishan.[10] He helped Shandong win the club's first Chinese Super League title in 11 years in his debut season, which was his personal 4th league title.[11] On 9 January 2022, he started in a 1-0 win against Shanghai Port in the 2021 Chinese FA Cup final, completing a domestic double.
Shanghai Port
After only one season, Xu would join fellow top tier club Shanghai Port on 18 April 2022.[12] He would make his debut for the club in a league game on 4 June 2022 against Wuhan Yangtze River in a 1–0 defeat, where he also received his first red card in his career.[13] He would later on go on to redeem himself when he scored his first goal for the club on 25 June 2022 in a league game against Wuhan Yangtze River once more in a 2–1 victory.[14]
On 29 October 2023, Xu won his fifth league title and first one with Shanghai Port after a 1–1 home draw against direct competitor and his former club Shandong Taishan. [15] He became only the second player in history to win the Chinese Super League with 3 different clubs after former Evergrande teammate Zheng Zhi.[16]
International career
On 11 November 2021, Xu made his international debut in a 1–1 draw against Oman in the third round of 2022 FIFA World Cup qualification. On 1 February 2022, he scored his first international goal in a 3–1 defeat against Vietnam in the same phase.
On 21 December 2023, Xu was named in China's squad for the 2023 AFC Asian Cup as replacement for Nico Yennaris.[17] He came on as a 58th minute substitute in the team's opening match against Tajikistan on 13 January 2024.[18]
^"扬科维奇的决定引发广泛争议,徐新难以胜任李可角色" [Li Ke left the team due to family reasons, and Xu Xin took the place of the national football team’s midfielder] (in Chinese). Sohu. 25 December 2023. Retrieved 16 January 2024.