The Italian is already a Chelsea legend, having served the club as a stylish midfielder between 1996 and 2002, when injury forced his retirement at the age of 31, and now rejoins the club to become an important member of backroom staff with top level coaching experience.
Di Matteo is best remembered at Stamford Bridge for his FA Cup final goals of 1997 and 2000, the first of which set a Wembley record for the earliest in a final after just 43 seconds.
The 41-year-old was most recently manager at West Bromwich Albion, where he achieved promotion to the Barclays Premier League at the first attempt before departing The Hawthorns in early February this year. He previously spent a season in charge of MK Dons.
Villas-Boas also brings with him to Stamford Bridge Jose Mario Rocha, a 48-year-old fitness expert who worked alongside the new manager at both his previous clubs, Porto and Academica.
Another new face will be Daniel Sousa, who will become head opposition scout, the role previously occupied by Villas-Boas in his first spell at the club between 2004 and 2007. Sousa also worked alongside Villas-Boas at each of his former clubs.
Following the success of last season’s reserve side, who became national champions, reserve coach Steve Holland will also step up to work with the senior squad, becoming an assistant first team coach, while Christophe Lollichon continues as goalkeeping coach.