Gianfranco Zola recently came in third in a poll concerning Chelsea fans' all-time greatest players, and the diminutive Sardinian is still held in high regard at Stamford Bridge. He retired as a player in 2005 and joined the Italian under-21 setup in a coaching role.
His first full managerial role was at Chelsea's London rivals, West Ham United. He brought class and flair to a workmanlike side and gave youngsters such as Jack Collison the chance to break into the first team. During his second season in charge there were signs that he could be heading for an early exit from Upton Park, as the Hammers chairman announced that the entire squad, bar Scott Parker, was for sale with apparently no consultation with his manager.
Zola left West Ham in 2010 and returned to management in 2012—this time at Championship side Watford. At the time of writing the Hornets are second in their league, with automatic promotion to the Premier League at stake.
Chelsea academy player Nathan Chalobah is currently on loan at Watford and would no doubt love to reunite with his current manager back at Stamford Bridge. Much as Zola is loved by the fans, there would need to be assurances that he would be treated better than Di Matteo for his appointment to sit comfortably with the faithful.