Early career Martinez came through the academy at
West Bromwich Albion from the age of 16. He was released from the club at the end of the 2019–20 season, one of five third-year scholars to not be offered a new contract.
Bristol Rovers Following his release from West Bromwich Albion, Martinez joined
League One side
Bristol Rovers in August 2020, initially joining up with the club's development squad. In early March 2021, Rovers' manager
Joey Barton revealed that Martinez, along with fellow development squad player
Zain Walker, had been training with the first-team squad. On 27 March 2021, Martinez made his debut for the club, playing the duration of a 1–0 home defeat to
Sunderland. After making eight appearances for the League One side as they finished bottom and were relegated to
League Two, the club exercised the option in Martinez's contract for another year. Martinez was released at the end of the
2021–22 season following Rovers' promotion back to League One.
Oxford City (loan) On 23 October 2020, Martinez joined
National League South side
Oxford City on an initial three-month loan deal as they looked to gain promotion. He made his debut for the club the following week, coming off of the bench in a 2–0 home defeat to
Hampton & Richmond Borough. He scored his first senior goal on 19 January 2021, in a 5–3 victory at
Hemel Hempstead Town, Martinez scoring his side's first goal to pull the scores back to 2–1 with a strike from 35 yards out.
Gloucester City (loan) On 4 March 2022, Martinez joined
Gloucester City on a one-month loan deal having found first-team opportunities hard to come by. By joining the
National League North club on loan, Martinez linked up with fellow Rovers loanees
Lucas Tomlinson and Ollie Hulbert as well as being managed again by former Bristol Rovers Development Squad manager
Lee Mansell.
Chippenham Town Following his release from
Bristol Rovers, he joined
National League South side
Chippenham Town on 15 July 2022 On 13 August 2022, Chippenham's home match against
Chelmsford City was postponed after Martinez had collapsed 27 minutes into the match. Following the match, Martinez's club issued a statement that his condition was not life-threatening. On 19 August, a further statement was released stating that Martinez had been fitted with a small heart monitor and would likely be able to return to playing football. On 22 April 2023, he made his return to first-team football as a stoppage time substitute against
Tonbridge Angels. ==Personal life==