El Tel wrote in The Sun: "Despite all of this goodwill, I still think it would be brave of him to embark on a second stint at a club where he was so successful and iconic first time around.
"Mourinho, who took over as Chelsea boss in 2004, won two Premier League titles in three years before leaving the club in 2007.
"He would be expected to match that impressive record. But there is a genuine risk his comeback could result in the shine being lost from his halo. Chelsea are no longer the Prem's biggest spenders as they were when he was first there.
"They are no longer an automatic choice to finish first or second, or even in the top four for that matter.
"Chelsea have the makings of an excellent squad, but there is still a lot of work to be done.
"His heralded return as boss is far from the cushy number it is being made out to be in some quarters.
"Mourinho has plenty to lose - not least his reputation."