When these two sides were drawn alongside Arsenal and Marseille, it was viewed by many to be one of the toughest groups in this season's Champions League.
Nevertheless, the previous campaign's finalists Borussia Dortmund were still expected to qualify for the knockout stages as group winners, with the rest left to battle for second spot.
However, following a 1-0 home loss to Arsenal last time out, Jurgen Klopp's men are now on the verge of having to settle for a place in the Europa League.
In fact, if they are to lose to Napoli on Tuesday evening and Arsenal avoid defeat against Marseille at the Emirates Stadium, then that would be the end of Dortmund's Champions League campaign.
Any positive result that the German side achieve will have to be done so without the presence of senior defenders Mats Hummels, Marcel Schmelzer and Nevan Subotic, all of whom have been ruled out with injuries.
Manuel Friedrich is also not permitted to play because he only recently joined the club on a free transfer to help ease the injury problems.
Polish full-back Lukasz Piszczek could be included, though, following a spell on the sidelines with a hip complaint. He came off the bench during the 3-0 defeat at the hands of Bayern Munich on Saturday.
Meanwhile, visiting manager Rafael Benitez will be without Giandomenico Mesto and Juan Zuniga because of knee complaints, but Marek Hamsik should feature, despite having started the weekend's clash against Parma as a substitute.
When the two sides met in Naples, the Italian outfit claimed the three points thanks to a 2-1 victory courtesy of goals from summer signing Gonzalo Higuain and Lorenzo Insigne.
Recent form
Dortmund: WWWLLL
Napoli: WWWWLL
Possible starting lineups
Dortmund: Weidenfeller, Grosskreutz, Piszczek, Papastathopoulos, Durm; Sahin, Blaszczykowski, Bender, Mkhitaryan, Reus; Lewandowski
Napoli: Reina; Armero, Albiol, Britos, Maggio; Behrami, İnler, Hamsik; Callejon, Insigne; Higuain
Sports Mole says: 1-1
Liam Apicella
