At a time when the Hammers are down in 15th position in the Premier League standings, Blackburn are second in the Championship as they bid for a return to the top flight.
Match preview
Having rested the many of his senior players for the trip to Romanian side FCSB in the Europa Conference League, David Moyes expected it to benefit his West Ham side against Crystal Palace on Sunday.
However, such was the standard of West Ham's performance that Moyes accepted that his side deserved to lose, even if it came courtesy of a last-gasp goal.
While Moyes is not under any immediate pressure at the London Stadium, West Ham have now lost eight of their 14 top-flight fixtures this campaign, scoring just 12 goals.
Given the level of players that were signed in the summer, the Hammers are performing well below expectations, and the Scot will recognise that his previous achievements will only stand him in good stead to a certain degree.
At a time when the East Londoners sit just two points above the relegation zone ahead of a key fixture with Leicester City on Sunday, Moyes requires a response from his squad in midweek.
As far as Blackburn are concerned, this tie is down on their list of priorities while they are holding down a position in the top two of the Championship.
Despite suffering eight defeats in 20 matches, Blackburn are second after winning the other 12, five of which have come from their last six outings.
The goals have dried up of late with Rovers failing to score more than twice in any of their most recent seven fixtures, but Jon Dahl Tomasson will be encouraged by just four being conceded at the other end over the same period.
Blackburn have overcome Hartlepool United and Bradford City to reach this stage of the competition, and they are making their first-ever visit to the London Stadium.
West Ham United form (all competitions):
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W
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Blackburn Rovers EFL Cup form:
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Blackburn Rovers form (all competitions):
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W
L
W
Team News
Declan Rice and Lucas Paqueta will almost certainly drop out of the West Ham XI, as well goalkeeper Lukasz Fabianski and forward Gianluca Scamacca.
Alphonse Areola, Flynn Downes, Manuel Lanzini and Michail Antonio are among the players who will be provided with a start, while Pablo Fornals should also feature.
The back four should line up as Vladimir Coufal, Nayef Aguerd, Angelo Ogbonna and Emerson Palmieri.
Although Blackburn do not play again until Sunday, it is against leaders Burnley, and Tomasson will want his players well rested for that fixture.
The majority of the team which started the 1-0 win over Huddersfield Town may drop down to the substitutes' bench or be rested, including Ben Brereton Diaz.
Tyrhys Dolan and Jack Vale should feature in the final third, with goalkeeper Aynsley Pears getting a rare opportunity between the sticks.
West Ham United possible starting lineup:
Areola; Coufal, Aguerd, Ogbonna, Palmieri; Soucek, Downes; Fornals, Lanzini, Benrahma; Antonio
Blackburn Rovers possible starting lineup:
Pears; Carter, Hyam, S.Wharton, Pickering; Morton, A.Wharton; Hedges, Dack, Dolan; Vale
We say: West Ham United 2-0 Blackburn Rovers
With Blackburn's priorities elsewhere, they are unlikely to put out a first-choice lineup. Given West Ham's superior strength-in-depth, it could prove to be a routine evening for the Hammers, who need to head into the World Cup break on a high note.