He initially struggled to cope following his father's death and also endured difficulties to pursue his cricket career due to the financial constraints faced by the family.
[6] On 3 June 2018, Mustafa was selected to play for the Toronto Nationals in the players' draft for the inaugural edition of the Global T20 Canada tournament.
[9] He made his List A debut for the UAE against Oman on 30 November 2007 during the 2007 ICC World Cricket League Division Two tournament.
In September 2014, he faced a major legal battle when a Dubai court banned him from entering the country for one year after being found guilty of absconding from duty.
[17][18] At the 2016 Asia Cup Qualifier, Mustafa scored 77 runs from 50 balls in the first match against Afghanistan, opening the batting with Muhammad Kaleem.
[22] In January 2018, he was named as the captain of the United Arab Emirates' squad for the 2018 ICC World Cricket League Division Two tournament.
During a crucial super six match between UAE and Zimbabwe during the 2018 World Cup Qualifier, he and Sean Williams were reprimanded for breaching Level 1 of the ICC Code of Conduct and were handed one demerit point each.
[31] In September 2019, he was named in the United Arab Emirates' squad for the 2019 ICC T20 World Cup Qualifier tournament in the UAE.