During the last two weeks Chelsea have seen themselves complete in three fixtures; FC Porto (Champions League), Tottenham Hotspur (FA Cup) and Manchester City (Premier League).
Despite there dominance this season and a multi-million pound squad it took a Frank Lampard (28 minutes) penalty to see off Manchester City at the City of Manchester Stadium last Wednesday.
The home side will line-up without Michael Essien who limped out the Blues FA Cup clash with their London rivals Tottenham Hotspur last Sunday (D 3-3) whilst long term injury Joe Cole (fractured foot) will also be out.
Chelsea and England full-back Wayne Bridge (knee) is also out whilst John Obi Mikel is suspended.
Predicted Blues Line-Up: Petr Cech, John Terry, Richardo Carvalho, Ashley Cole, Ndjitap Geremi, Frank Lampard, Claude Makelele, Michael Ballack, Salomon Kalou, Didier Drogba, Arjen Robben.
Sheffield United meanwhile have gone a fortnight without playing a competitive fixture, only a 3-0 win at Manchester United in the Premier League Reserve League North sets up this tie.
Sheffield United welcome back Midfield duo Michael Tonge and Nick Montgomery who return from suspension, the pair missed the Blades last fixture when they drew 1-1 with Everton at Bramall lane.
The Blades go to Stamford Bridge without Chris Lucketti and Matthew Kilgallon, the Defensive duo are out a bruised foot and an ankle injuries respectively.
Neil Warnock is expected to go with a 4-5-1 formation like he unsuccessfully played at Liverpool in that 4-0 reverse but should he play the traditional 4-4-2 then Egyptian international Ahmed Fathi could be in with a shout for a re-call.
Predicted Blades Line-Up: Paddy Kenny, Derek Geary, Phil Jagielka, Chris Morgan, Chris Armstrong, Nick Montgomery, Keith Gillespie, Michael Tonge, Colin Kazim-Richards, Rob Hulse, Christian Nade.
Man in the Middle: Chris Foy (Merseyside)
This is Mr. Foy's second game in charge this season involving Sheffield United having previously took charge when Middlesbrough overcame the Blades (3-1) at the Riverside on New Years Day.