Steve Round, the Manchester United assistant manager, believes the club's £27.5m signing Marouane Fellaini is the complete midfielder they have been searching for.

Fellaini joined close to Monday's 11pm transfer deadline for £4.5m more than his buyout clause, after this was allowed to expire by the manager, David Moyes, who believed he could be acquired for less.

"When David came here he looked at the squad and thought one of the players we needed to bring in was someone with those physical attributes in the middle of midfield who could give us strength and aggression in certain games and maybe allow one or two of the others to play," Round, who was also Moyes's assistant at Everton, told the Manchester Evening News. "That, coupled with his ability to score, made him feel Marouane would be a really good acquisition for United. When you get to work with him every day, you get to realise that technically he is excellent.

"He is a 10 to 15 goals a season man and that is good from midfield. He can play No4, sat in front of the defence, he can play an eight in the centre doing box-to-box and can play a No10 where he drops off the front man. That's valuable when the range of games is so varied.

"His chest control is arguably one of the best in the world. You can bang the ball at him from anywhere and he will bring it down on his chest and bring others into play. His feet and his technique work are really good. He is aggressive and tackles. He also has great fitness stats. He will regularly do over 12k a game and he can run, goodness me he can run. He is a lot better footballer than he gets credit for and he has good passing ability."

Round believes Fellaini offers a new dimension to United. "He doesn't have the same range as a Michael Carrick in his long passing but his continuity and the way he keeps the ball and short passing is very good," he said. "When you are building a squad to compete on all fronts you don't want every single player to be the same. You want options and differences. In a certain game it might be Tom Cleverley and Carrick in midfield, it might be Fellaini and Carrick, or Fellaini and Anderson. It has given the manager options he didn't have before.

"Marouane was ready for this step up. He'll fit in well with the professionalism here and relish the challenge. I am sure Marouane will settle in very quickly and be an integral part of United's success in the future, I really do."

Round has no doubts that Moyes will be a success as Sir Alex Ferguson's replacement. "Without a doubt David was ready for this job," he said. "I had five years at Everton with him and he impressed me every day. There is not a day goes by where you take your foot off the gas with him. He is 100% every day with an incredible work ethic. He also has an incredible desire to succeed. He now has the stature and presence to move to a club like this. I really do believe he will be a big success here.

"Now I have been in this club and environment I can understand why Sir Alex and the board appointed him, to keep that continuity, work ethic, drive and feeling about the club going. It was very important to them and I can understand now that I have been here and lived it. They were made for each other."