The former England international joined on deadline day from Tottenham Hotspur on a free in January 2022, becoming Frank Lampard's first signing at the club.
Things never got going for Alli at Goodison Park though, similarly to how it had fizzled out for him at Spurs.
Alli played 11 games in the second half of the 2021-22 season, mostly as a substitute, but he did have a role to play in their crucial comeback win over Crystal Palace which kept them up in the penultimate game of the season, inadvertently setting up Richarlison's equaliser.
However, after coming on as substitute against Aston Villa on the second weekend of the following season, Alli has not featured for the club since, 18 months on.
Injury and a disappointing loan move to Besiktas means Alli is yet to feature under Dyche, who has provided an update on the player.
Speaking to Sky Sports about when Alli could return, Dyche revealed: "We'll see, he's got a long way to go and we have deliberately kept him back from it and I agreed that with him just to give him time and give him space, so that's what we're doing. Hopefully he'll be back, we don't know.
"We're giving him the privacy that he needs at this time. He's in a good state, I spoke to him recently and had a good, long conversation with him. Making sense of another injury is difficult but he'll come through that I'm sure," Dyche added.
The 27-year-old underwent groin surgery in January which might potentially end his season, and with his contract up in the summer, it could see Alli not play for Everton again.
Despite returning to training in December, another setback hit Alli as he was edging in on a comeback, joining many other Everton midfielders on the sidelines, as Abdoulaye Doucoure, Amadou Onana, Dwight McNeil and Andre Gomes were all struck down with injury at a similar time.
Given Everton's perilous financial situation though, it could save them a fair amount of money, as Alli is seven appearances away from triggering a clause in his contract that would see the club owe Spurs £10m.
The clubs were believed to be in contact about coming to a resolution and changing the terms of the deal, but as of now, nothing has changed.
However, with Alli's injury likely to keep him out for much of the season, it is highly unlikely he would return in time to play seven matches, and with no talks of contracts negotiations being opened, he may leave for nothing at the end of the season.