Can the Blades blunt the champions' charge?

What happens when the unstoppable force meets the very movable object? Chelsea have spent the season making a mockery of the Premier Division, but on Sunday week they will have to pick themselves up from the unfamiliar taste of defeat when Sheffield United come to town.

Rotherham United's 2-1 win over the champions today was a jolt to the system, only Chelsea's second league loss of the campaign and their first since the opening weeks. The Blues' lead at the top has been cut to sixteen points, though that is still a chasm, and their home form remains imperious: no visiting side has won at their ground in the league this season.

Sheffield United, for their part, are in a scrap at the other end of the table. Seventeenth, a single point above the drop zone, they have picked up four points from their last two games, including a 2-0 win over Wolverhampton Wanderers on New Year's Day and a 1-1 draw with Everton today. But the Blades have not beaten Chelsea in the league since a 1-1 draw in April 2051, and their visits to Chelsea have been particularly painful: a 5-0 drubbing in January 2060 and a 4-1 loss the following November.

Chelsea will be without Jairzinho, whose damaged achilles tendon has kept him out since September, and Thomas Verlhac, who is still recovering from concussion. Sheffield United's own injury list includes Aron Backman, out with a broken upper arm, and Giovane, who twisted his knee today and is doubtful.

But for all their dominance, Chelsea have shown a vulnerability in recent weeks. The defeat at Rotherham was their second in three league games, following the 2-1 win over Stoke City and the 2-0 victory over Reading. Sheffield United, meanwhile, have been steadily improving under pressure.

For the neutral, the question is whether Sheffield United can make the most of Chelsea's rare wobble. For the champions, it is a chance to reassert their authority. As one Chelsea insider put it after today's defeat: 'We don't do losing streaks. We'll be ready.'

The Blades may travel more in hope than expectation, but in a season of surprises, they will believe they can add another.