London - Premier League leaders Chelsea and beleaguered Liverpool will be among the teams bidding to take a step closer to Wembley when the League Cup reaches the quarter-final stage this week.
Both sides face second-tier opposition, with Chelsea visiting Derby County on Tuesday and Liverpool travelling to new Championship leaders Bournemouth on Wednesday.
In the only all-Premier League tie, Tottenham Hotspur host Newcastle United, while the third division's sole representatives, Sheffield United, host out-of-form Southampton.
The League Cup holds special significance for Chelsea manager Jose Mourinho, as he won the 2005 tournament in his first season at the club and went on to lift the trophy for a second time in 2007.
Chelsea have made a sensational start to the campaign, losing only one of their first 24 games in all competitions, but goalkeeper Petr Cech says they cannot be compared to the great teams of the past until they win something.
"This team has huge potential," said the Czech, who stood in for the injured Thibaut Courtois in Saturday's 2-0 win over Hull City and is expected to keep his place for the trip to Pride Park.
"It has been doing really well this season, we are top of the league and have been doing some brilliant games.
"But we are empty-handed at the moment, and I don't like to compare the teams until the season is finished."
Derby, coached by former England manager Steve McClaren, currently sit third in the Championship, a point below Bournemouth and second-place Middlesbrough, and are bidding to reach the semi-finals for the first time since 2009.
While Chelsea have been in cruise control since mid-August, Liverpool's campaign has lurched from one disaster to another.
Brendan Rodgers' side crashed to a demoralising 3-0 defeat at arch rivals Manchester United in the league on Sunday, days after limping out of the Champions League in the group phase.
As such, a positive result at Bournemouth would help to banish some of the storm-clouds gathering over the club, but Eddie Howe's team are riding the crest of a wave after sinking Cardiff City 5-3 on Saturday to claim top spot in the Championship.
"Everybody that works here works extremely hard," Bournemouth assistant coach Jason Tindall told BBC radio.
"That's our ethos, that's our philosophy, and it's nice to see we're performing well and getting our rewards for all the hard work that everybody has put in."
Bournemouth, who famously dumped holders Manchester United out of the FA Cup in 1984, will be appearing in the League Cup quarter-finals for the first time.
Tottenham and Newcastle approach their encounter at White Hart Lane on Wednesday on the back of contrasting results in the league.
Spurs climbed to seventh place in the table after Christian Eriksen scored an 89th-minute winner in a 2-1 win against Swansea City on Sunday, whereas Newcastle crashed to a 4-1 defeat at Arsenal.
"We have a massive cup tie now and then if we can just get through this period now with another seven, eight or maybe nine points, then we are going to be in a great position and that is what we have to focus on," said Newcastle manager Alan Pardew, whose side had ended Chelsea's unbeaten start to the campaign in their previous outing.
Southampton are desperate for a positive result after a run of four straight defeats that has seen them slip out of the Champions League places.
But in Sheffield United they face a team with impressive recent cup pedigree, as demonstrated by their run to the FA Cup semi-finals earlier this year.
Fixtures (Kickoff for all games is at 21:45 CAT)
Derby County v Chelsea, Sheffield United v Southampton
Bournemouth v Liverpool, Tottenham Hotspur v Newcastle United