United have improved in the league this term and could yet win the FA Cup with a final showdown against Chelsea booked for May 19 at Wembley.
But the failure to compete with City – combined with the hugely disappointing Champions League exit at the hands of Sevilla – will ensure Mourinho targets a number of players this summer.
But this will mean offloading a few members of the current squad and Nicholas believes Fellaini, Shaw, Rojo and Mata could all be on their way.
Asked about Belgium international Fellaini and whether he will stay at Old Trafford beyond the summer, he told Sky Sports: Well after scoring the winner against Arsenal Im not his biggest fan!
He was one of the players who was brought in for the sake of it under a desperate David Moyes, but we can see hes not technically good enough to stay at United.
If theyre going to bring in a few other players this summer then youd think hed be offloaded along with the likes of Luke Shaw, Juan Mata and Marcos Rojo to make room.
Matt Le Tissier, the former Southampton and England striker, reckons Fellaini will extend his stay at United but says he is symbolic of a negative style of football that is frustrating fans at the Theatre of Dreams.
I guess from a managers perspective he gives you a different option, he said. Will he start 30 games next season? No, probably not.
Hes just a squad player who gives you a use in certain situation and Manchester United should be better than having throw on the big lad as their plan B.
I think Mourinho will keep him around because he likes to have options but for the fans I think he represents what they are frustrated at in terms of the style he represents.