We profile select group who've played for both clubs.
BOLO ZENDEN (CFC 2001-04, SAFC 2009-11)
Zenden arrived at Chelsea with an impressive record. He had a Dutch Cup and Eredivisie title from first side PSV Eindhoven in his trophy cabinet and also won La Liga with Barcelona in 1998-99. His time at Chelsea was less successful however, with just an FA Cup runners-up medal to show for his three seasons at the club, a time blighted by injuries. He scored four goals in over 50 first team appearances at Stamford Bridge and moved on a permanent deal to Middlesbrough following an initial loan spell.
The Stadium of Light was the former Dutch international’s last stop in his playing career. Following his release from Marseille, Steve Bruce snapped up the experienced midfielder in October 2009. He scored his first Sunderland goal against Chelsea in January 2010, less than 10 seconds after coming on as a substitute. Zenden’s role was restricted mainly to substitute appearances, but he endeared himself to the Sunderland faithful with a string of hard-working performances. He scored in his final game for Sunderland, a 3-0 win over West Ham on the final day of the 2010-11 season.
Just recently the Dutchman returned to Stamford Bridge. Following the appointment of Rafa Benitez as manager of the Blues, Zenden was reacquainted with his former boss when he accepted the assistant manager role.
EMERSON THOME (CFC 1999-2000, SAFC 2000-03)
The imposing Brazilian defender arrived in England towards the end of the 1997-98 season, signing for Sheffield Wednesday. After a successful stint at Hillsborough, with over 50 league appearances spread over three seasons, Chelsea swooped to sign Thome in December 1999. Even though he was used mainly as a back-up to the first-choice pairing of Marcel Desailly and Frank Leboeuf, he made 20 league appearances in the 1999/2000 campaign.
One match into the 2000/01 season, Thome made the switch to the Stadium of Light. He made a bright start to his Black Cats career, with almost 40 appearances over the course of his first season at Sunderland. He struggled with injuries over the next few campaigns and joined Bolton Wanderers on a free transfer in the summer of 2003.
GARETH HALL (CFC 1986-1996, SAFC 1996-98)
The Croydon-born defender started as an apprentice at Stamford Bridge before making the step up to the first team in 1987. He made over 130 appearances, even though his chances were somewhat limited by the presence of Steve Clarke.
He initially moved to Sunderland on loan at the end of 1995 and made the move to Roker Park permanent in January 1996. He was part of the side that came top of the old First Division and were subsequently relegated from the Premiership the following year. Following the club’s relegation, he played some part in the unsuccessful bid for promotion the following campaign, before departing for Swindon in 1998.
BRYAN ‘POP’ ROBSON (SAFC: three spells as a player between 1974-84, one game as caretaker manager in 1984, CFC: 1982-3)
Despite his early career as a Magpie, Robson is fondly remembered by the Black Cat faithful. He moved to Roker Park in 1974 after a spell at West Ham for the first of his three spells with the Black Cats. His goals twice helped Sunderland to promotion, as Second Division champions in 1976, and as runners up in 1980.
He was a player/coach at Chelsea in 1982, scoring three goals in 15 appearances at Stamford Bridge.
Robson returned to Sunderland in 1983 for his third and final spell at the club. He was recalled to the team at the age of 38 years and 182 days for the final game of the 1983-84 season against Leicester. Robson scored his last ever Sunderland goal in a 2-0 win that saved the team from relegation. He also managed the team for a single game in 1984 following the sacking of Alan Durban. After a number of coaching roles, Robson is currently chief scout at Sunderland.