Chelsea play Atletico Madrid in Champions League Group C on Wednesday night.
Here Press Association Sport looks at the Spanish side in focus.
DIEGOS
Striker Diego Costa finally has been granted his wish to return to Atletico after three years and two Premier League titles with Chelsea. The Brazil-born Spain striker will be reunited with Diego Simeone, the much admired Atletico boss best remembered by English audiences for being the recipient of David Beckham’s petulant kick in England’s second-round loss to Argentina at the 1998 World Cup.
Simeone has never lost to English opposition as a coach, winning three of the five contests.
Costa will hope Simeone can help him extract revenge on Chelsea.
CHELSEA CONNECTION
As well as Costa, who will be able to play for Atletico again once their transfer embargo is lifted in January, there are other familiar faces in opposition. Filipe Luis and Fernando Torres, plus Tiago, who is now an assistant coach, all had spells at Stamford Bridge.
Belgium goalkeeper Thibaut Courtois spent three years on loan at Atletico from Chelsea, winning La Liga in 2013-14. Radamel Falcao, now at Monaco, had a successful spell at Atletico and an underwhelming one at Chelsea.
Torres is one of several players who have a connection with both Chelsea and Atletico.
PREVIOUS MEETINGS
Chelsea have one win in five European games against Atletico – the first meeting in October 2009. The sides most recently met in the 2013-14 semi-finals.
Courtois was permitted to play under UEFA rules. Goalless after the first leg, Atletico won 3-1 at Stamford Bridge to advance to a Madrid derby in the Lisbon final.
Real Madrid won La Decima (their 10th European Cup), after more than a decade of trying. But Atletico had won the league title for the first time in 18 years, breaking the Real-Barcelona hegemony.
Atletico knocked Chelsea out at the semi-final stage in 2014.
FORM
Atletico are unbeaten in 11 games in all competitions, including the final four matches of last season. They opened their Champions League campaign with a goalless draw at Roma.
Atletico have conceded one goal in their last five games following last Saturday’s 2-0 win over Sevilla at the Metropolitano.
Atletico warmed up for their Champions League clash with a 2-0 win over Sevilla.
METROPOLITANO
Chelsea may be envious of Atletico’s modern new home. Los Rojiblancos moved from the fabulous but crumbling Vincente Calderon Stadium this season, playing their first home match at their new ground on September 16 – a 1-0 win over Malaga.
Chelsea are considering a rebuild of Stamford Bridge and would likely welcome the influx of foreign investment which has seen Chinese conglomerate Wanda sponsor the Metropolitano.
Atletico’s players and fans have instantly settled in at their new stadium.