Alex Matos played for Norwich's Under-16s in their 1-0 win over Ipswich in the Hospital Cup on 8th May 2018. He was called up to England's Under-15 squad for their clash with Belgium in February 2019. He is a student at the Langley School where he was part of the team that won the Norfolk Schools’ County Cup for Under-12s in May 2017 with Matos scoring twice in the final against Sprowston High School.

He was previously with Luton Town and interested Arsenal and Tottenham before joining Norwich. His brother Jeyda Matos had a trial with Norwich. As a ten-year-old, Matos was viewed as one of hottest young talents in English football but former City academy chief Gregg Broughton helped convince the youngster to swap Kenilworth Road for Norfolk

Alex made his debut for Norwich's Under-18s on 31st October 2020 in a 5-1 defeat at Arsenal after stepping up from the under-16s. He scored Norwich's only goal. He finished the 2020/21 season with six goals and registered five assists in just 11 appearances in the U18 Premier League.

On 16th July 2021 it was confirmed he was awarded a scholarship deal with Norwich. He signed his first professional contract on 20th October 2021 despite competition from a number of top sides including Chelsea. He then missed a large part of 2021/22 through injury.

Although he struggled to progress in the 2022/23 season with the Under-23s, he was linked with a move to Chelsea on a free transfer on 24th March 2023 with Matos having played a trial game for their Under-23s against Charlton alongside N'Golo Kante and recorded two assists in a 3-0 win. The deal is expected to be a free transfer with add-ons. He will become part of Jim Fraser's Under-21 squad which is seeking to be English-dominated. Southampton and Newcastle were also reported to be interested.

Teh switch to Chelsea was confimed on 3rd May 2023

Matos was on the Chelsea bench for their Premier League clash with Bournemouth on 17th September 2023. He made his professional debut coming on as a 89th minute substitute in Chelsea's 2-0 win at neighbours Fulham on 2nd October 2023.

On 2nd January 2024 he was linked with a loan move to Huddersfield to hasten his development. This was confirmed on 4th January 2024 and he made his debut for Huddersfield in the FA Cup third round defeat at Manchester City on 7th January 2024. His 20 appearances and 1 goal were not enough to prevent Huddersfield from relegation on 4th May 2024.

On 24th May 2024, Matos was called up to the England Men's Elite Squad (formerly known as the Under-20s) for friendlies with Sweden and the Republic of Ireland in June 2024.