The Toffees have had a disappointing campaign so far, and their most recent home defeat against Swansea City was a hugely frustrating result.
Everton were beaten 2-1 by the struggling Swans, and Keys says that Everton are a side playing well within themselves.
"What on earth is happening at Everton," he wrote. "Have you noticed the recent form? It's now just one win in 10 - v Newcastle. Their only home wins this season have come against the two other teams in the bottom 3 - Sunderland and Villa - and a struggling Chelsea early on.
"They're exactly where they were a year ago in the table. Despite a very good squad and a nice few bob spent, there's no sign of improvement. I fear for the Goodison faithful up there.
"Look. There's a good chance they'll get past City this week, but I doubt it. What then? Lukaku will want to go in the summer, for sure. His ambition extends further than mid-table mediocrity with Everton. As for Stones - I'd sell him now and re-invest the money. I'm not convinced by him."
John Stones was partly at fault for gifting Swansea a goal in the fixture and he struggled throughout the match.
The youngster is still considered one of the finest talents in the world, but Everton’s defensive record this season has been woeful.
Lukaku, meanwhile, has scored with great frequency and his performances have caught the eye.
The 22-year-old is said to be of interest to Manchester United by The Sun and the Toffees face a huge fight to keep hold of the powerful striker if they are unable to make it into Europe.