Julen Lopetegui's side staved off interest from Juventus and Barcelona to secure the services of Martial on loan in January after limited opportunities at Old Trafford this season.
Rangnick confirmed in December that the 26-year-old wanted to leave due to a lack of first-team chances – he had played the full 90 minutes of a game only once this season and featured for just eight minutes since the German's arrival.
Martial has since registered 297 minutes of action for Sevilla across all competitions, with Lopetegui's team second in LaLiga - 10 points behind Real Madrid - and still in contention for the Europa League.
Sevilla faces West Ham in the return leg of its last-16 clash on Friday (AEDT) in Europe's secondary club competition, and Martial will be hoping to add to his current tally of one goal in six games.
Despite not finding his feet in front of goal as of yet, Martial expressed how much he is enjoying life in Spain.
"For me, it was the best option to play and enjoy football again. I lost it [love for the game] a little bit in Manchester because I was not playing," Martial said.
"I feel very good in Sevilla. The city is very good and we are a good team so, for me, it's perfect. I'm playing so I'm happy.
"But I'm here just until the end of the season and that's it."
Martial became the most expensive teenager in history at the time when he completed a move worth up to £58million (€69m) from Monaco in 2015.
The France international hit the ground running in Manchester, finishing the 2019-2020 campaign as United's top scorer with 23 goals.
However, the arrival of Rangnick caused problems after a well-publicised rift between the pair following the German's claims that Martial refused to feature against Aston Villa, which the player denied.
"I asked United to leave because I wanted to play," he said. "I still have a contract but they know what I want, so we will see at the end of the season.
"When he [Rangnick] arrived, my objective was to leave. I told him I wanted to leave and that's it.
"He talked to me and said, 'If you want to stay, with the way you train you will play if you keep training like that'. But I wanted to have a new atmosphere and a new club."
Martial refused to suggest he will use the Sevilla loan as a chance to prove a point to United, but he will use the opportunity to show his worth to France ahead of the 2022 World Cup in Qatar.
"I'm just going there to win and help the team," he continued. "I don't care what people say about me. Really.
"The World Cup for me is an objective. I want to be part of this group and that's why I'm here because I want to play and show I can be in the squad. I need to show my quality and score goals."