The Blues occupy 10th spot following a 2-2 draw with Everton before the international break, while the Lions are one place worse off thanks to a 3-0 success over Bournemouth.
Match preview
Just when the pressure on Graham Potter's shoulders was slowly being lifted, the under-fire Englishman once again felt the full force of fans' frustrations, as Everton twice came from behind to travel back to Merseyside with a point in the bag.
Following a goalless and largely forgettable opening 45 minutes, Joao Felix and Kai Havertz put Chelsea ahead on two separate occasions, but Everton struck back both times through Abdoulaye Doucoure and Ellis Simms, who bagged his first Toffees goal on the 89-minute mark.
That four-goal stalemate quickly snapped a three-game winning run for the Blues, who are perennial occupants of 10th place in the standings, but Liverpool - who boast a game in hand - are only four points better off in sixth place.
While hopes of Champions League qualification are surely too far-fetched for Potter's crop, the consolation prize of Europa League football is a distinct possibility for the Blues, who are now at least unbeaten in four games and have scored at least twice in each of their last three contests.
Inconsistency on their own patch continues to bedevil Chelsea too, as only three of their last nine Premier League home matches has ended in victory, and only 26 top-flight goals have been scored at Stamford Bridge this term - the fewest out of all 20 grounds.
Prior to their trip to Villa Park, Bournemouth had fought valiantly against Manchester City, were agonisingly close to denying league leaders Arsenal and comfortably kept Liverpool at bay in a 1-0 win over the Reds, but Unai Emery's side enjoyed plenty of bites at the Cherries.
Taking just seven minutes to draw first blood through Douglas Luiz, patience was soon the name of the game for Villa, but the Lions struck twice more in the final 10 minutes through Jacob Ramsey and Emiliano Buendia to put Bournemouth to the sword with aplomb.
With 10 points to show from their last four Premier League matches, the international break arguably came at the worst time for the 11th-placed Lions, who only sit behind Chelsea on goal difference and could break into the top half should results go their way this weekend.
Since the ex-Arsenal boss returned to the Premier League landscape, Villa have scored in all of their 16 competitive matches under Emery, and the last time they went five top-flight games unbeaten, the fifth game in that pattern was a 1-1 draw away to Chelsea.
However, the Blues ran out 2-0 winners at Villa Park back in October - largely thanks to some inspired goalkeeping by Kepa Arrizabalaga - and only one of the Lions' last 17 trips to Stamford Bridge has ended in victory.
Chelsea Premier League form:
D
L
L
W
W
D
Chelsea form (all competitions):
L
L
W
W
W
D
Aston Villa Premier League form:
L
L
W
W
D
W
Team News
Working with injury and illness concerns in the double figures, Chelsea will certainly be without Armando Broja and Thiago Silva this week, and doubts are lingering over a wealth of other first-team regular fixtures.
Kai Havertz (illness) and Reece James (thigh) were both forced out of international duty midway through the break, while all of Mason Mount, Pierre-Emerick Aubameyang, Raheem Sterling, Edouard Mendy, Wesley Fofana and Cesar Azpilicueta will need assessing too.
James's England withdrawal was thought to have been more precautionary than anything else, though, while Havertz will also likely recover from a bout of flu in time to lead the line.
Meanwhile, it is largely as you were in the Villa infirmary, but Poland right-back Matty Cash is now said to be facing three weeks out with a calf injury sustained against the Czech Republic.
Cash is joined on the treatment table by Jed Steer, Boubacar Kamara, Leander Dendoncker and Philippe Coutinho - all of whom should not be out for much longer - and Ashley Young should earn an immediate recall to the right flank.
Emery otherwise has no reason to alter a winning formula, as Ollie Watkins aims to become the first player in Villa's history to score in five successive Premier League away games, but he has met Chelsea five times without making the net ripple.
Chelsea possible starting lineup:
Kepa; Badiashile, Koulibaly, Cucurella; James, Fernandez, Kovacic, Chilwell; Mudryk, Havertz, Felix
Aston Villa possible starting lineup:
Martinez; Young, Konsa, Mings, Moreno; McGinn, Luiz; Bailey, Buendia, Ramsey; Watkins
We say: Chelsea 1-1 Aston Villa
Consistently troubling opposing defences under Emery, Villa's sensational scoring run under the Spaniard should not cease at Stamford Bridge, where Chelsea have hardly typified consistency.