This is the decisive game of Chelsea’s 10th Champions League quarter-final tie, with Porto the nominal away side in Seville. The Blues, who progressed this far in the competition without a loss for the first time – a club record – are the only remaining team yet to concede in the knockout stage.

This tie feels far from over, especially as some of the Dragons’ claws may return in the form of players back from suspension, and the away goals rule could benefit the Primeira Liga’s last remaining ambassadors.

Yet statistics are stacked against Sergio Conceicao’s team, who have never successfully overturned a first-leg deficit of more than one goal in 15 previous attempts.

One Chelsea goal scored would mean Porto, who lost 2-0 in the first leg (their fourth first-leg home European knockout defeat by more than the minimum), will need to score three. A neutral stadium deprived of feverish supporters may not appear conducive to a night of such heroics.

Porto may be grateful tonight’s venue is not Stamford Bridge, where they have only ever tasted defeat. But it is an away ground for both, and Chelsea’s record on the road is the best in the competition: played five, won five, with a goal difference of +12. Porto’s, they will not need reminding, is the worst: played four, won two, lost two, goal difference +1.

This quick return to Andalusia’s capital city brings the genuine novelty of a ‘home from home’ tie, and both clubs can draw on fond memories for inspiration. Chelsea have a 100 per cent record from two visits to the Ramon Sanchez Pizjuan: 4-0 against Sevilla and 2-0 last Wednesday. The Portuguese can look back to winning the UEFA Cup there in 2003 under Jose Mourinho.

Chelsea team news

The Premier League goals scored at Crystal Palace were by some distance the quickest so far under Thomas Tuchel and the 4-1 final scoreline is the biggest victory of his tenure.

Portuguese media noted Chelsea could barely have had an easier ride before this second leg, and the hosts did play into the Blues’ hands, taking risks in their defensive third. You would think that less likely in the second leg of a Champions League quarter-final, yet both the Londoners’ first-leg goals came from individual brilliance capitalising on Porto errors.

Zaidu Sanusi was deceived by Mason Mount’s appliance of science, while a colleague’s pass fizzed off unfamiliar right-back Jesus Corona, who lost the deposit on his bottle as Chilwell set off on a sparkling run.

It was a measure of the Blues’ control that Mount’s finish closed a nine-man move. Chilly’s goal was his third for the Londoners, two of which were scored with his less-favoured right boot.

When pinned back by Chelsea, especially through Chilwell and Reece James, Porto conceded ground and reformed as a deep-lying 5-3-2 formation. At other times, we could have made hay in the inviting acreage behind Porto’s high-line of defence with bolder, more accurate or better-weighted passes.

Will Hakim Ziyech be a feature of this leg, as the Dragons take more risks to draw blood?

At the weekend Chelsea were purposeful, fluid and energetic from the outset, and those are virtues that can be applied no matter the opposition or setting. The Blues have led at the break in six of the past eight games in this competition.

Injury and suspension ensured Kurt Zouma started at Selhurst Park. Porto won the majority of aerial encounters last Wednesday and on Saturday the France defender scored his fifth goal to become the Premier League’s highest-scoring defender.

That said, Andreas Christensen’s calm and accurate passing and numerous clearances played a big part in the Blues’ success that night. The Dane, who missed out at the weekend, has travelled to Andalusia.Other options on show in south London included Callum Hudson-Odoi’s adventure at right wing-back, as well as Christian Pulisic and Kai Havertz rediscovering the net. Will that pair and Mount form the attacking trio again tonight?

Dragon ball

Two big players have served their first-leg suspension and could be back tonight for Porto, who won 2-0 at Tondela on Saturday evening. Sergio Oliveira recovered sufficiently from a training ground injury to come off the bench and is likely to be a big presence in midfield.

Oliveira, who is creative, strong in the air and also a threat from direct free-kicks, has contributed more than one in three of Porto’s 14 goals in this year’s competition. Yet Sergio Conceicao admitted it would have been a risk to start his key man at the weekend and has even hinted at retaining Marko Grujic tonight.

Also returning, as Moussa Marega’s strike partner, is Mehdi Tarema who could provide the cutting edge the Dragons lacked last week. The Iran forward, who took two bites of the cherry to notch the Dragons’ second at the weekend, has an abundance in the Primeira Liga and one Champions League goal to his name.

Toni Martinez (a late sub last week) and Evanilson were among the weekend starters as the head coach looked to players who ‘work hard with and without ball’, perhaps with an eye to matching the Blues’ physicality.

Conceicao set his team up for the first leg in a 4-3-3 formation, his forwards often going man-for-man against the Blues’ back three, led by the hard-working Marega.

Behind them, two of their central midfielders, Grujic and Mateus Uribe, stayed deep while Otavio had some success getting behind the Chelsea middle with one-twos. The hosts also won dangerous free-kicks and corners but were unable to make their aerial dominance count on the night. We may see Zouma involved for that reason.

Mount regularly had to drop back to help out but, happily, the Londoners’ backline remained resolute and few attacks turned into clear-cut chances.

A different Porto tactic was to withdraw into their own half, hoping to regain possession and exploit any gaps left by the advancing Blues midfield. Fit-again N’Golo Kante’s presence may help close off those opportunities this evening, although he may not start.

How to watch Porto-Chelsea

This match will be covered live by BT Sport in the UK. To find the relevant broadcaster where you are, see UEFA’s TV guide.

Chelsea TV’s global available matchday shows – including early team news, exclusive interviews and analysis – are on the 5th Stand app, Facebook Live, and the official YouTube channel.

Last-four details

The winners of this tie will meet either Liverpool or Real Madrid in a two-legged semi-final, with match dates yet to be fixed. Eden Hazard’s team have a 3-1 first-leg lead going into tomorrow’s decisive game at Anfield.

For those who make it, the Champions League final is set for Saturday 29 May 2021 at the Ataturk Olympic Stadium in Istanbul, Turkey.

Champions League regulations

Coaches are permitted to select 12 substitutes and introduce five of them in three different spells (plus half-time) throughout the course of the match. Porto have had the benefit of this all season in the Primeira Liga.The Video Assistant Referee system is used in all games and viewing the pitch-side monitor is more prevalent than in the Premier League.

The away-goals rule, favouring the side that has scored more goals on the road, applies at the end of normal time. Only a 2-0 win for Porto could lead to extra-time and, if necessary, penalty kicks.

All yellow cards are cleared after these quarter-final second legs, even pending suspensions where a player receives a third caution.

First successful UEFA semi-final

Tomorrow is the 50th anniversary of 23-year-old Blues striker Derek Smethurst dispatching Dave Webb’s lob to score the decisive goal of the home leg of the 1970/71 Cup Winners’ Cup semi-final against Saturday’s FA Cup opponents, Manchester City.

Chelsea won the away leg by the same margin to reach a European final for the first time, facing Real Madrid in Athens. Dave Sexton’s men would triumph 2-1 in the replay after the final finished 1-1, adding a second star to the club badge.

Matchday rarity

The match day programme for this game will be a collector’s item: the only one produced for a ‘home’ match not staged at Stamford Bridge. It can can be bought online for £3.50 plus postage.

Champions League quarter-final first leg fixtures

TuesdayChelsea v Porto (agg 2-0) 8pm (Seville)Paris Saint Germain v Bayern Munich (agg 3-2) 8pm (Paris)

WednesdayDortmund v Manchester City (agg 1-2) 8pm (Dortmund)Liverpool v Real Madrid (agg 1-3) 8pm (Liverpool)