Bruno Fernandes' suspension opened up a spot in the side, but despite Amad Diallo and Antony being available, right-back Mazraoui was named as the number 10 for what proved to be a 1-1 draw in Istanbul.
Mazraoui played his part in Man United's breakthrough goal in Turkey, and Ten Hag explained his thinking ahead of the match, insisting that the 26-year-old is capable of operating in an advanced area.
"We have some injuries and a suspension with Bruno, so we had to be creative. Also, we had some players who have a short turnaround to West Ham [on Sunday], so we've made some changes there and a different set-up, but not so much different because we want to keep consistency," the manager told TNT Sports,.
"[Christian] Eriksen, Manu [Manuel Ugarte] as a 6 and we bring Nous Mazraoui in the 10 position. I know from Ajax that sometimes I played him there. As a full-back in our system, he's playing in the half spaces, so he is capable of doing this job. He can bring good pressing.
Mazraoui played as a number 10 in Man United's draw with Fenerbahce
"We can see during the game what is needed, so we maybe go with him in another position and maybe, if needed, he can play a more offensive position and it's also possible to bring Casemiro in."
After the match, Man United goalkeeper Andre Onana praised Mazraoui's performance against Fenerbahce, claiming that the defender was "brilliant for the team".
"He did a good job for us. We're happy with him and happy with his performance," said Onana. "He used to play there when he was younger so I think, sometimes, we have to be pragmatic, no, with the red cards and injuries.
"So players need some time to step up. That's what Mazraoui did and he was brilliant for the team because the team needed him there and I'm happy with him."
Mourinho 'not surprised' by Mazraoui's role
Fenerbahce head coach Jose Mourinho also discussed the tactical call after the match, with the Portuguese 'not surprised' that Mazraoui was used as an attacker in the European fixture.
"The situation with Mazraoui, for you was maybe a big surprise," said the home team's manager. "But not for us because Sofyan Amrabat told me Mazraoui can play in this position.
"He did it a lot with Erik ten Hag in Ajax. he has the qualities. He's not Bruno but he has the legs to press."
Fernandes will be available for Sunday's Premier League clash against West Ham United, but fellow midfielders Mason Mount, Kobbie Mainoo and Toby Collyer could again miss out.
Mazraoui has been an important player for the Red Devils since his arrival from Bayern Munich over the summer, making 12 appearances in all competitions, contributing one assist in the process.