A lot has happened in the six months since the sides last met, but Bayern remain the overwhelming favourites to advance to the quarter-finals, where Napoli or Barcelona await.
In the entire history of the European Cup and Champions League, no team has ever won by three or more goals in the first leg of a knockout match away from home and failed to progress, going through on all 92 previous occasions.
That stat alone tells you the magnitude of the task Chelsea face, and they do not exactly enter the match full of confidence after losing last weekend's FA Cup final to Arsenal.
This season will still be reflected on as a positive one for Frank Lampard in his debut campaign in charge, though, having succeeded in guiding the club into the top four of the Premier League despite operating under a transfer ban.
In the Champions League, the West London outfit just advanced through a tricky group that also contained Valencia, Lille and Ajax.
Being paired with Bayern in the first knockout round brought back good memories for Chelsea fans when the draw was made way back in December, with this a repeat of the 2012 final which they won.
In the first competitive meeting between the sides since that day, however, it proved to be a nightmare for Lampard as Bayern produced a classy display to run away with the first leg.
Bayern will no doubt have one eye on next week's quarter-final with Barcelona or Napoli - that tie being locked at 1-1 at the midway stage - though Hansi Flick is expected to still field a strong side on Saturday.
That is due to the Bavarians needing to build up their fitness, having not played competitively for more than a month.
Bayern's most recent game was the DFB-Pokal final against Bayer Leverkusen on July 4 - Lewandowski taking his season's tally to 52 goals with another brace in Berlin as Bayern ran out 4-2 winners.
Flick's men also wrapped up the Bundesliga title with time to spare - something not many would have predicted last December - seeing out the domestic campaign with 16 successive wins.
The Bayern boss has made a huge impact since succeeding Niko Kovac and is looking to become only the third manager in Champions League history to win his first five matches in charge, after Fabio Capello and Luis Fernandez.
On the basis of the first leg and their form since then, the German champions may just be favourites to go all the way in this year's tournament to make it a famous treble.
Bayern Munich Champions League form: WWWWWW
Bayern Munich form (all competitions): WWWWWW
Chelsea Champions League form: WWDDWL
Chelsea form (all competitions): LWWLWL
Gnabry netted twice in the reverse fixture and was the match-winner for Bayern in their friendly win over Marseille on Friday.
Flick has indicated that he will field a strong lineup this weekend, so Gnabry and prolific striker Lewandowski seem certain to start, along with assist king Thomas Muller.
Lampard has a decision to make with regards to who starts in goal, with Kepa Arrizabalaga having been dropped for the last two matches.
Bayern Munich possible starting lineup:
Neuer; Kimmich, Boateng, Alaba, Davies; Goretzka, Thiago; Gnabry, Muller, Perisic; Lewandowski
Chelsea possible starting lineup:
Caballero; Zouma, Christensen, Rudiger; James, Barkley, Kovacic, Emerson; Mount, Giroud, Hudson-Odoi
We say: Bayern Munich 2-1 Chelsea (5-1 aggregate)
Playing at the Allianz Arena will bring back happy memories for Chelsea, but they face an almighty task if they are to prolong their European campaign beyond this weekend. The Blues are winless in their last seven away Champions League matches in the knockout stages, while Bayern have won 17 games in a row in all competitions, so we can only see this tie ending one way.