The versatile 19-year-old has started Arsenal's opening two matches of the season — the Community Shield and Premier League wins over Manchester City and Coventry City respectively — yet United sources retain optimism a deal could still be struck before the 1 September deadline, according to The Sun.
Lewis-Skelly's recent involvement owes much to circumstance rather than a change in Arsenal's stance on his future. Well-placed sources say his starting role has been shaped by Martin Zubimendi's dip in form and the delayed return of Mikel Merino, who was involved in Spain's World Cup final victory over the summer.
Arsenal value Lewis-Skelly at north of £50million, a figure Manchester United and Chelsea have so far been unwilling to meet, and that gap has strengthened Mikel Arteta's confidence that the academy graduate will remain at the Emirates Stadium. Arteta has previously said he is "100 per cent" certain Lewis-Skelly will stay.
The teenager's rise has not been entirely smooth. He started in only two Premier League matches before the closing weeks of last season, with Arteta previously citing question marks over his maturity.
He nonetheless started Arsenal's Champions League semi-final second-leg win over Atlético Madrid and their final defeat to Paris Saint-Germain, underlining his growing importance in the biggest matches.
United's interest in Lewis-Skelly comes amid an unresolved search for a left-back before the transfer window shuts. Newcastle United's Lewis Hall had been United's leading target, but the Magpies have moved to play down any suggestion of a departure after already banking close to £250million this summer from the sales of Anthony Gordon, Sandro Tonali and Bruno Guimarães.
United are prepared to sanction the sale of Harry Amass, the 19-year-old left-back who featured in pre-season but missed out on Saturday's 2-0 defeat at Hull City.
Luke Shaw, now in his 13th season at Old Trafford, is entering the final year of his contract without the option of a further season, adding urgency to United's search. Barcelona's decision to pass on their option to sign Marcus Rashford has also pushed the left-back pursuit back up United's list of priorities.