Watt now plays for non-league Maidstone United.
He told The Sun: "I have never met anyone like Jose in football and don't think I ever will.
"His man-management was on a different level. Players would go out on that pitch willing to die for him.
"On that first day we were called into Stamford Bridge for a meeting, which was strange in itself as these things would usually be held at the training ground.
"He had us in a room overlooking the pitch and it was deliberate because one of the first things he said was we would never lose at home - whether it was in the league, the cups or Europe.
"Jose had an aura about him, and if there were any of the boys who had doubts about him they were won over straight away.
"I've never met a manager who was more thorough. The preparation was the same, whether we were playing Barcelona or Scunthorpe.
"You would go in every day excited about what the day had in store and that was as much down to Jose as a person as anything else."