Both Arsenal and Villa are at least guaranteed a place in the qualifiers, but will hope to qualify directly for the round of 16 by finishing in the top eight.
Arsenal has two matches remaining, starting with Wednesday's match against Dinamo Zagreb. Depending on other results, a win could confirm Mikel Arteta's side's eighth-place finish.
Villa's chances suffered after their 1-0 defeat to Monaco on Tuesday, but they remain in the top eight ahead of their final league match against Celtic.
Celtic ranks 23rd in the table, two places ahead of the elimination places.
Brendan Rodgers' side will face Young Boys – who are bottom of the table and without a point in the Champions League this season – at Celtic Park on Wednesday.
A win would almost certainly guarantee Celtic a place in the play-offs.
Manchester City is one place and one point behind Celtic, which is ranked 24th.
Pep Guardiola's side face an arduous trip to Paris Saint-Germain on Wednesday ahead of their home match against Club Brugge in Round 8.
A win over Paris Saint-Germain would significantly boost City's chances of qualifying for the knockout rounds, but it would not guarantee it.
A thrilling finale will be guaranteed on January 29 when all 18 final matches will be played at the same time at 20:00 GMT.
