The League One new boys have already faced one Premier League opponent Stateside this month, holding Bournemouth to a creditable 1-1 draw in their second summer battle.
Match preview
The month of May was initially very merry for Chelsea and Mauricio Pochettino, whose Blues side sneaked back into UEFA competition in the Europa Conference League courtesy of a splendid five-game winning streak in their last five Premier League fixtures.
Chelsea's sixth-placed ranking would have been enough for Europa League qualification, but Manchester United's FA Cup success bumped the Blues down to the third tier of continental football, where Pochettino will not be barking orders from the touchline.
Talk of the sack had been prevalent throughout Chelsea's difficult periods in 2023-24, but their end-of-season revival led to the belief that Pochettino would stick around for 2024-25. Todd Boehly and co, however, had a different path in mind, controversially severing ties with the England-linked Argentine.
Instead, Championship-winning head coach Maresca assumes control of the reins following his successful promotion mission with Leicester City, who almost suffered a calamitous collapse in the closing stage of the campaign but ultimately staved off Ipswich Town's title charge.
Wednesday's showdown will represent one of five transatlantic contests on Chelsea's agenda, as the Blues also face Celtic, Club America, Manchester City and Real Madrid in their quintuple-header, before returning home to host Inter Milan at Stamford Bridge.
As Chelsea gear up for their opening contest of the summer, Wrexham have already pitted their wits against two foes in exhibition action, crushing Hanley Town 5-1 on July 13 before also boarding the plane destined for the United States.
South Coast outfit Bournemouth were first up for Phil Parkinson's side, who went into the break a goal to the good on Saturday thanks to James Hill heading into his own net, but the Cherries struck back eight minutes into the second period through Marcos Senesi.
Wrexham were not short of chances to snatch a late victory, albeit while also calling on goalkeeper Arthur Okonkwo to save their bacon on occasion, and a low-scoring stalemate against Premier League opposition was certainly a praiseworthy result for Parkinson's crop.
Once Wednesday's battle with the Blues is done and dusted, Wrexham make a quick jaunt to Canada to face the Vancouver Whitecaps on July 27, before returning to home territory and hosting Fleetwood Town in their final friendly battle of the summer.
However, the third-tier outfit possess painful memories of their exhibition game against Chelsea this time last year, having suffered a 5-0 beatdown at the hands of their Premier League foes, whom they have not faced in a competitive setting since 1982.
Wrexham friendly form:
Team News
Talk about a baptism of fire; in Maresca's first few weeks in the Chelsea chair, the Blues boss is having to deal with the fallout of a racism scandal involving Enzo Fernandez, who filmed himself and some of his Argentinian teammates singing an offensive song about French people after their Copa America triumph.
Fernandez's chants are being investigated by the authorities, but he will not take part in Wednesday's fixture anyway, and nor will Euro 2024 winner Marc Cucurella, Cole Palmer, Conor Gallagher, Moises Caicedo or Gabriel Slonina, who is representing the USA at the Paris Olympics.
Djordje Petrovic and Mykhaylo Mudryk might be involved, however - the pair both suffered group-stage exits at the Euros - while Robert Sanchez and Nicolas Jackson missed the end of the campaign through injury and may not be risked from the start.
A plethora of new signings should be involved, though, as Kiernan Dewsbury-Hall, Omari Kellyman, Marc Guiu, Renato Veiga and Tosin Adarabioyo all endeavour to make their Chelsea debuts.
Wrexham are unsurprisingly unaffected by international call-ups, but revered striker Paul Mullin will not be involved at Levi's Stadium, as the 29-year-old is on the mend following a back operation.
Left-back Jacob Mendy has also undergone a procedure to repair a damaged Achilles tendon and will sit this one out too, but Anthony Forde was back from his own layoff against Bournemouth, where no other players left the field with any injuries to report.
Chelsea possible starting lineup:
Kepa; James, Disasi, Adarabioyo, Colwill; Dewsbury-Hall, Veiga; Madueke, Nkunku, Sterling; Guiu
Wrexham possible starting lineup:
Okonkwo; Brunt, O'Connell, Cleworth; Bolton, Jones, Evans, Cannon, McClean; Dalby, Marriott
We say: Chelsea 3-1 Wrexham
Wrexham could afford a large pat on the back for their performance against Bournemouth and should take the game to an out-of-practice Chelsea side, who are sure to be at least partially affected by the Fernandez scandal.