The France international discussed Mourinho's management style with RMC Sport (via Tom Coast of Sport Witness) and said he wanted to prove the Portuguese coach wrong after being omitted from his starting XI when he took over at Old Trafford:
"It's true that I'd have preferred it if he'd told me directly, there's no need to say it in front of everybody. After that, you definitely want to prove him wrong. He didn't start me during the first few games and each time I came on, I scored.
"In the end, he told me: 'You see, now you understand what I wanted'. It can get to you. You just want to show him you deserve to be on the pitch."
Mourinho succeeded Louis van Gaal at United in 2016-17, and Martial made only 18 Premier League starts in the coach's first term. The attacker scored four goals and provided six assists during the league campaign, frustrating Mourinho with his lack of productivity.
However, Martial made 10 appearances in the UEFA Europa League that season, with the Red Devils winning the competition and qualifying for the UEFA Champions League. United also won the EFL Cup.
Mourinho's second season saw United finish second in the Premier League, but the manager was sacked during his third campaign in December 2018. The club were in sixth place at the time.
The former Monaco player struggled for game time while Zlatan Ibrahimovic and Wayne Rooney were present in Mourinho's attack, and the industrious work of Marcus Rashford and Jesse Lingard was often favoured over Martial's contributions.
Martial had previously lost the shirt to Ibrahimovic in 2016, but Solskjaer rewarded the player with the prestigious number.
The 24-year-old's striking displays have been hit or miss this season. Martial has netted 10 goals and provided three assists in the Premier League and Europe.
Further weight of expectations are currently on the player's shoulders after an injury to Rashford, and Martial must keep finding the back of the net if United want to penetrate the top-four.