It's been a frantic few European months for Manchester City.
After getting a two-year European ban overturned by CAS, Pep Guardiola's men headed over to Lisbon in the hope of picking up a first Champions League trophy in the club's history.
Manchester City Last 5: WLWDW
Manchester City come into the game on the back of a much-needed 1-0 victory over Arsenal on Saturday evening.
It was the first win in three for the Manchester outfit, who also picked up their first clean sheet of the season as Pep outwitted his former right-hand man, Mikel Arteta.
Having had no pre-season campaign due to their involvements in the latter stages of last seasons Champions League, Pep will be looking for his men to kick on this side of the international break.
Porto Last 5: W W L D /
Despite being the top-seeded side in Group C, Porto head to the Etihad in the knowledge that they are the big underdogs in what should be a very competitive group.
Like their opponents, Porto have also had a mixed start to their domestic campaign.
After opening their season with big wins over Braga and Boavista, the Dragões fell to a shock home defeat to Maritimo before dropping another two points in a 2-2 draw at Sporting Lisbon last time out.
There are no new injury concerns for Pep Guardiola, who will once again be without their key duo of Aymeric Laporte and Kevin De Bruyne.
Sergio Aguero - who completed a first 65 minutes of action since June in Saturday's win - looks set to start once more as City's only other senior striker - Gabriel Jesus - remains on the sidelines with the muscle injury picked up in their 3-1 win at Molineaux.
Versatile full-back Oleksandr Zinchenko is available for selection for the first time this season after overcoming his injury troubles, whilst Pep has also suggested that Ilkay Gundogan may be handed a first start of the season.
Porto too will be without one of their defensive stars, Spanish centre half Ivan Marcano remains out after rupturing his cruciate ligament back in March.
The only other injury concern for the Portuguese outfit is their Senegalese stopper Mouhamed Mbaye after he also ruptured his cruciate ligament in September.
And of course, there will also be no Alex Telles for the visitors after the Brazilian ended his four-year stint with the club when he joined Manchester United on Deadline Day.
Whilst there will be five group stage games to follow, both sides will know how important it is to get off to a fast start before the fixtures start to pile up.
The Citizens have a stellar record in the group stage in recent years - topping the group in their last three campaigns - and they are big favourites to make it four from four.
It won't be easy, but they should have enough to get past a Porto side who are yet to get going this season.
Prediction: Manchester City 2-0 FC Porto