While the visitors have already qualified for the knockout stages, Porto must hope that Olympiacos fail to beat Marseille for their route into the next round to be confirmed this week.
Porto are a team who know exactly what it takes to reach the Champions League knockout stages, although topping a group which includes Man City was always going to be a step too far for Sergio Conceicao's crop.
Nevertheless, Porto will secure qualification for the next round should they stop Guardiola's side from winning this week, but even if Conceicao's side suffer another defeat to the Premier League giants, they will be guaranteed to finish second if Olympiacos fail to take maximum points from their encounter with Marseille.
Porto are currently six points clear of Olympiacos and already have one foot firmly in the knockout stages, but qualification has not been confirmed just yet and Conceicao's side cannot afford to become complacement at this crucial time in Group C.
However, the Portuguese double winners are in spectacular form and go into this bout having won their last five on the bounce in all competitions - scoring 11 and conceding just one - with Conceicao's side overcoming Santa Clara 1-0 at the weekend.
This week's hosts will not have fond memories of their trip to the Etihad last month, though, as City eased to a 3-1 victory over Porto thanks to goals from Sergio Aguero, Ilkay Gundogan and Ferran Torres.
Manchester City, as expected, have swept aside the competition in the Champions League group stage and qualified for the knockout rounds without needing to hit second gear.
With 10 goals scored and only one conceded in four matches, Pep Guardiola will be delighted that his side have been able to secure a path to the next stage with minimal difficulty, allowing the Spaniard to focus on turning his side's fortunes around in the Premier League.
The Citizens have endured a mixed bag of results early on in the top-flight campaign, and their record in front of goal has also left a lot to be desired at times, but Guardiola's men needed no second invitation to stamp their authority on an out-of-sorts Burnley side at the Etihad on Saturday.
Riyad Mahrez staked his claim for a regular starting role with a hat-trick against the Clarets, while Benjamin Mendy marked his return from injury with a goal and Torres increased his tally across all competitions to five strikes in a resounding 5-0 victory.
Should Man City maintain their 100% record in the 2020-21 Champions League with victory at the Estadio do Dragao, their first-placed finish in Group C will be confirmed before Guardiola's men welcome a winless and goalless Marseille to Manchester in their final group-stage match.
Porto Champions League form: LWWW
Porto form (all competitions): LWWWWW
Manchester City Champions League form: WWWW
Manchester City form (all competitions): WWDLWW
Porto midfielder Mateus Uribe was not involved in last week's win over Marseille due to an abscess, but the Colombian should be fit enough to start this encounter after coming off the bench against Santa Clara.
The 29-year-old makes a timely return to the fold with Marko Grujic suspended for this encounter - the Liverpool loanee was given his marching orders against Marseille for two bookable offences.
As for Man City, Aguero's knee problem flared up before the visit of Burnley and the prolific Argentine was forced to miss out - he remains a doubt for the trip to Portugal as well.
Porto possible starting lineup:
Marchesin; Manafa, Mbemba, Sarr, Sanusi; Uribe, Otavio, Oliveira; Corona, Marega, Diaz
Manchester City possible starting lineup:
Ederson; Cancelo, Dias, Laporte, Zinchenko; Rodri, De Bruyne, Foden; Silva, Jesus, Sterling
We say: Porto 1-2 Manchester City
This is sure to be Man City's toughest game of the group stage so far, with Porto boasting a solid defensive record in recent matches and looking to assure themselves of a place in the last 16. Guardiola is expected to rotate heavily and the hosts will certainly fancy their chances, but we still think that City will have enough firepower to get over the line.