The Carlos Tevez derby: A rivalry like no other
If you know, you know
When Carlos Tevez and Javier Mascherano signed for West Ham United from Corinthians in 2006, there was widespread shock in the Premier League.
What few people expected those was quite the impact that the former would have on the that season's relegation battle. Thanks in no small part to Tevez, West Ham survived that season at the expense of Neil Warnock's Sheffield United.
In the final match of the season, Tevez scored the only goal in a win against the champions and his future club Manchester United. Combined with the Blades' failure to beat Wigan Athletic on the same day, the Hammers stayed up.
This infuriated Sheffield United, as did the revelation that the deal to bring Tevez and Mascherano to the club broke rules surrounding third party ownership rules.
A court case would eventually award £20 million in compensation to Sheffield United, but the bad blood hasn't ended with a judge's ruling.
As the two sides prepare to face other this weekend, we travelled to Bramall Lane this weekend, we spoke to some Sheffield United fans who admitted that, while time has passed, this unusual rivalry remains passionate.