Keane believes there are some positive signs but believes defence to be the main problem area that needs to be rectified in the upcoming transfer window.
"I think there was certainly a feel-good factor back at United over the last number of games," Keane told Sky Sports.
"In the back of your mind, if [Paul] Pogba can get back, if people like [Marcus] Rashford can get fit for the end of the season it will be a big, big boost for them. There's a definitely a feel-good factor.
"But it's still a long way back for United. They're a long way behind City and, obviously Liverpool.
"The signs are a lot better than they were six or 12 months ago; the signings have settled in very, very well and will get better with time.
"If they can have a good finish to the season - if we get round to playing games - and if they can get one or two very good players again in the summer, then it's another big step.
"I think in terms of recovery there's still a bit to go yet. Every time you're talking about the big clubs, you talk about attacking players. I still think they need one or two defenders.
"I'm still not convinced by the centre halves, I'm certainly not convinced with Shaw. [Brandon] Williams has done well as a young kid in that side.
"I know they've been linked with a number of players - [Jack] Grealish, [James] Maddison - nobody springs to mind. I've not had my breakfast yet, you've caught me off guard."