Everton are currently searching for their next manager after sacking Roberto Martinez.
Everton parted company with manager Roberto Martinez last week after a disappointing campaign for the club.
They finished 11th in the table, failing to secure a top ten place for the second season running.
The new manager at the club is expected to be busy in the summer transfer window, with new investor Farhad Moshiri reportedly offering a big transfer budget for his first season in charge.
And Keys believes that it will be needed, as the club will require a huge rebuilding job this summer.
“There’s a huge re-building job to be done,” he wrote on his website.
“The likes of [Leon] Osman, [Gareth] Barry, [Phil] Jagielka and [Tony] Hibbert are all over 30 now. [Romelu] Lukaku will leave. So will [John] Stones.”
It will certainly be interesting to see if Lukaku and Stones leave Everton this summer given how heavily they have been linked with exits.
Lukaku in particular seems destined to go, with his agent appearing to be determined to get his client to a top European side.
The change in management could change that though as both are sure to be keen to see who arrives at Goodison Park, with a big name appointment potentially tempting them to stay.