The Blades were beaten 5-0 by Brighton at Bramall Lane this afternoon, a result which has seen them set an unwanted record.
No team has ever let in as many goals as Chris Wilder's side at this stage of a campaign in the modern era and in top-flight history, there hasn't been a worst start since 1964.
The defeat was United's third straight home game in all competitions which they have conceded five goals with two of those losses coming against Brighton.
It leaves the forlorn Blades already on -43 goal difference and they're looking set to smash the long-standing current record.
That is held by Derby County, who in their infamous 11-point season finished on a woeful -69 goal difference.
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Derby also hold the record for the most goals conceded in a 38-game Premier League campaign with 89.
Sheffield United have already let in 65 which gives them an average of 2.6 per game.
If they keep that rate of letting goals in up, they can reach a tally of 98 goals conceded, setting an unwanted record in emphatic fashion.
Wilder's men could even break the 42-game season record of 100 goals let in which was set by Swindon Town in 1993/94.
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To make matters worse for United, the heavy defeat to Brighton included an own-goal from Jack Robinson as he poked into his own net from close range.
The Blades have scored the most own-goals (4) in the Premier League this season and it's a club-record too.
Robinson turned into his own net to make it 3-0 at the time but a brace from Simon Adingra made it 5-0 by the end of the game.
And that took Sheffield United's tally of home goals conceded this campaign up to 36, which is the third-worst ever in English top-flight history after only 13 matches.
Only Darwen in 1891-92 (43) and Aston Villa in 1935-36 (41) have ever shipped more.
Their awful defensive record combined with also scoring the least in the Premier League leaves them looking destined for relegation.