Sevilla announced the temporary signing of the France international on Tuesday, with Martial moving to LaLiga until the end of the season.
While the finances behind the deal have not been revealed, it was reported that it will cost Sevilla roughly €6million, a fee that combines Martial's salary and a loan fee.
Sevilla sporting director Monchi did appear to confirm Martial took a pay cut to get the deal over the line, as United apparently wanted the forward's reported £240,000-a-week (€287,000) wages covered in full.
United interim boss Ralf Rangnick revealed last month that Martial wanted out after struggling for first-team football – he has played the full 90 minutes of a game only once this season and featured for just eight minutes since Rangnick's first game in early December.
Martial considers finding enjoyment again to be his priority.
"For me, it was just about the feeling I had with the manager [Julen Lopetegui], and I decided that at the moment I wanted to come to Sevilla," he said.
"I spoke with him [Lopetegui] a few times, he was very excited to see me coming here to play.
"For me, it's a good club. Whatever, it's not just about money, it's to play and enjoy. That's it, that's why I chose to come here: to play and enjoy football again.
"I feel excited, it's a good club in Spain. I come to help and do a great job. I know they have good players, I'm just coming to help, give my best and try to win a trophy for the fans."
🆕 Check out @AnthonyMartial's first 24 hours as a Sevillista! ⚪🔴— Sevilla FC (@SevillaFC_ENG) January 26, 2022
During a behind-the-scenes video of Martial's arrival and introduction to the club, Monchi thanked the striker for making the move happen.
"Thank you, in front of the president and vice president, for the effort you made to come here," he said.
"For us, it's important that a player wants to come here, but even more so that they want to come so much they make some economic sacrifices. It's an honour for us."
When you wake up and realise it wasn’t a dream and Tony Martial is still here 😃 pic.twitter.com/TamRDamv54— Sevilla FC (@SevillaFC_ENG) January 26, 2022
Martial could make his Sevilla debut against Osasuna after the international break.
He joins the club second in LaLiga and just four points behind leaders Real Madrid, with Lopetegui's men hoping to defy the odds by claiming a first league title since 1945-1946.
Tony Martial, he came from France... 🎶 pic.twitter.com/ApvrufN3Jz— Sevilla FC (@SevillaFC_ENG) January 25, 2022
They also remain in Europe and next month face Dinamo Zagreb in the knockout round play-offs of the Europa League, the final of which is to be held in Sevilla's Ramon Sanchez Pizjuan stadium in May.