On matchday six just last season, these two met in a winner takes all showdown.
Atleti prevailed 3-1 in Northern Portugal, thereby pipping Porto to second spot, in a game that witnessed three red cards.
This time, not quite so much is on the line.
Last Wednesday evening, Porto hammered run-away group leaders Club Brugge 4-0 Jan Breydelstadion.
Mehdi Taremi bagged a brace, Evanilson and Stephen Eustáquio also scored, while Diogo Costa saved two penalties in quick succession.
Later that night, Atleti played out a thoroughly entertaining game with Bayer Leverkusen at Cívitas Metropolitano.
With the score 2-2, after full time, Atlético Madrid were awarded a penalty, needing to win to keep alive their qualification hopes.
Yannick Carrasco stepped up, saw his effort saved, Saúl Ñíguez then headed onto the crossbar, before Reinildo’s effort was inadvertently blocked on the line by Carrasco’s heal.
So, los Colchoneros come into matchday six for points below their hosts, thereby unable to qualify for the round of 16.
Pressure on Diego Simeone further mounted on Saturday with his team beaten 3-2 by La Liga strugglers Cádiz.
Here, Atleti need to match Leverkusen’s result to just get into the Europa League.
Porto meantime will be looking to better Club Brugge’s result, thereby pipping the Belgian club to first place.
The Portuguese champions have only won two of 11 meetings with Atleti, but look set to improve that ratio at Estádio do Dragão.