Dean Smith's side pulled off a priceless victory over Arsenal on Tuesday night to climb out of the relegation zone, but their plight remains perilous with only goal difference keeping them out of the bottom three.
This match has long been tipped as the crucial final-day showdown as far as the relegation battle is concerned, although West Ham's recent improvement has ensured that they go into the final day with their Premier League status already secured.
For Aston Villa there is still plenty of work to be done, but they have at least given themselves a fighting chance and the completion of a remarkable escape is now in their own hands.
Just two weeks prior to Sunday's match, Villa looked destined for the drop with seven points separating them from safety following a spell which saw them pick up just two points from 30 on offer in the league.
Victory over Crystal Palace on July 12 kick-started their revival, though, and a subsequent draw at Everton and a shock home win over an in-form Arsenal side have seen them climb out of the bottom three for the first time since February.
Smith's side are by no means clear of danger, though; they only sit the right side of the dotted line by virtue of their goal difference, which is superior than 18th-placed Watford by only one, meaning that Villa could win on the final day but still go down if Watford win by two goals more.
Villa will have one eye on Watford's trip to Arsenal, then, but if both of them lose then Bournemouth will also come back into play and could secure survival themselves by beating Everton at Goodison Park.
The recent improvement in form - picking up more points in their last three games than they had in their previous 13 - will certainly give the visitors optimism that they can hold up their end of the bargain, and on paper they also have the easiest final-day match with West Ham already safe.
There are plenty of statistics which suggest that Villa could need a helping hand from elsewhere, though, not least their dreadful away form which has seen them fail to win any of their last nine and only one of their last 16 on the road across all competitions.
You have to go back to January 2016 for their last away clean sheet in the Premier League, and their standing as the league's second-worst defence could still come back to haunt them with goal difference possibly coming into play.
Villa have also failed to win any of their last eight games on the final day of a season - losing six of those - and they will no doubt be pleased that this is not also a must-win game for their hosts.
It was not long ago that this looked like it could be a winner-takes-all affair for both teams, but the Hammers have won three and lost just one of their last six games to move away from danger - officially guaranteeing safety with a 1-1 draw at Manchester United last time out.
West Ham have now amassed as many points from their last six games as they had from their previous 17, and victories over fellow strugglers Norwich City and Watford in that time have been particularly crucial.
While survival is something to celebrate, David Moyes will want more from his side than merely avoiding relegation next season and the number one area for improvement will no doubt be their home form.
Victory on Sunday would see them record successive home league wins for the first time in 10 months, but they could also fall to a club-record-equalling 10th home league defeat of the season - only Southampton and Norwich City have lost more times on their own turf this term.
West Ham must also improve at holding on to leads; Wednesday's draw at Old Trafford made it 26 points they have thrown away from winning positions this season, and if you were to add that to their current points tally then they would sit third in the table and be battling for Champions League qualification on the final day, rather than survival.
West Ham Premier League form: WDLWWD
Aston Villa Premier League form: LLLWDW
Neither injury is thought to be serious, but Moyes is unlikely to take any unnecessary risks over their fitness on the final day unless they are 100% ready.
Andriy Yarmolenko, Felipe Anderson and Manuel Lanzini are among the names who could be in the frame to start should Bowen fall short, but otherwise Moyes is unlikely to make sweeping changes to an in-form team.
Tomas Soucek has also been in decent scoring form and he is set to start for the first time since making his loan move permanent, while Declan Rice could be making his last West Ham appearance if reports linking him with a summer move away are to be believed.
West Ham possible starting lineup:
Fabianski; Johnson, Diop, Ogbonna, Masuaku; Rice, Soucek; Yarmolenko, Noble, Fornals; Antonio
Aston Villa possible starting lineup:
Reina; Guilbert, Konsa, Mings, Targett; McGinn, Luiz, Hourihane; Trezeguet, Samatta, Grealish
We say: West Ham 1-2 Aston Villa
Most of the usual reference points for predictions suggest a West Ham win in this one, but the final day can throw up surprise results and with so much riding on this game for Villa, we are backing the visitors to get a result.
Smith's side will need to tighten up at the back and defy their poor away form against a team on a good run, and we are expecting the prize of possible Premier League survival to be enough to inspire them to do exactly that.