Manchester United's latest signing Nemanja Matić has said it was "a very easy decision" to the Red Devils, but insists he is still not 100 percent fit.

Matić joined United from Chelsea on the final day of July after the two clubs agreed a fee of approximately £40 million. It is the second time the Matić has worked with manager José Mourinho, who signed the Serbian during his reign at Chelsea from Portuguese club Benfica.

Matić delighted to join one of the biggest clubs in the world

"I feel great," said the midfielder in his first interview with MUTV, calling the Red Devils "one of the biggest clubs in the world" and adding: "I am very happy because I am now part of this great club, part of this great group. I am looking forward to starting to train with the team and starting to play games."

On the chance to work with Mourinho again after a season apart Serbian international Matić added: "Also, my wish was to train with José and, of course, when you have a club like him and a club like Manchester United is, you don’t need to think a lot so my decision was very easy."

Matić hailed Mourinho as "a great coach" and insisted that the Portuguese coach "always took the best" from him when they worked together at Stamford Bridge.

The 29-year-old continued: "I improve if I work with him, so I am very happy to be again with him. When the coach wants you to come to the club, it gives you motivation, more possibility and I will give my best to show that I deserve to be in this club and part of this group."

"I am not 100 per-cent ready, but I will be very soon"

Matić trained away from Chelsea’s first-team before his move to United and despite moving to a new club, he still hasn't joined his new team-mates in training.

United's new No.31 has a challenge on his hands to be fit for the start for his new club's first game of the new season on the at home to West Ham United on August 13.

Matić revealed that he "trained alone with a fitness coach" in his first few sessions at United, explaining: "It's not the same when you train alone, but I have enough time before the season to prepare myself. I am not 100 per-cent ready, but I will be very soon."

Matić believes his new club has the potential to go on and do big things this season starting with the UEFA Super Cup in Skopje, the capital of Macedonia, next Tuesday.

The midfielder declared himself "happy" to "have some days to train before the first big game" against Real Madrid in the Super Cup, insisting that he is "sure this season" that "all together" United can "do big things."