The 50-year-old Portuguese coach said he is on his way to London to close out the formalities of a return to Stamford Bridge after his exit from Real Madrid was confirmed.
Harris, who made more than 600 appearances for Chelsea between 1961 and 1980, is in no doubt Mourinho can push the club back into contention for a first Premier League title since 2010. “If you have a look at every club Jose has been to, he has always been successful,” Harris told Press Association Sport.
“People will say he has not done that well at Real Madrid, but he took an unfashionable club like Porto to winning the Champions League, and did the same thing at Inter Milan.
“If he was to come back to Chelsea again, and with one or two adjustments to the squad they will be a major force, challenging for all the major honours again next season.