Chelsea faces Swansea City in the Capital One Cup semifinal on Wednesday. And while the debate on whether Fernando Torres will start the game ahead of new arrival Demba Ba is bound to fill column inches in the build-up, the emergence of David Luiz in his new midfield role could be the most significant.
Chelsea's Brazilian defender-cum-midfielder has impressed in his new role of late, but on Wednesday, Luiz will be tasked with the challenge of silencing the ever-impressive Michu, who scored again over the weekend as the Swans drew 2-2 with Arsenal in the FA Cup.
With a squad boasting some of the world's finest talent, the Blues are odds-on favourites to lift the Capital One Cup this term, but they will face a Swansea side with threats of its own.
We look at some of the key matchups in what promises to be a fascinating cup tie.
Swansea City's Michu celebrates his strike against Arsenal on Sunday
The debate continues as to where David Luiz should feature for Chelsea—at the heart of defence or in midfield.
For now, it seems, Rafa Benitez has settled for the latter, meaning the Brazilian will be tasked with a whole lot more than his usual midfield duties come Wednesday—namely, keeping a watchful eye on Swansea's Spanish midfielder Michu.
There's no doubting the former Rayo Vallecano man has been one of the signings of the season, and his goal in the 2-2 draw against Arsenal in the FA Cup on Sunday (on virtually his first touch) was his 15th in what has already been a prolific season.
When Chelsea faced the Swans at the Liberty Stadium in early November, they kept Michu relatively quiet, but he was playing as the lead striker on that occasion. With Danny Graham back among the Swansea goalscorers, Michu has dropped back into his more familiar role as an attacking midfielder in recent games.
With the Spaniard playing a little deeper, David Luiz will have to work hard to track his late runs into the box that have proved so deadly this term.
Chelsea's Brazilian ace has certainly proved adept in his new position, but facing Michu in the first leg of the Capital One Cup semifinal on Wednesday could be his biggest challenge yet.
Eden Hazard has enjoyed a successful start to his Chelsea career
He was caught out by Kieran Gibbs' excellent movement that led to the Arsenal defender putting the Gunners 2-1 up in the FA Cup tie at the Liberty Stadium over the weekend, and Swansea City's Dwight Tiendalli will be in for another busy 90 minutes when he comes face-to-face with Eden Hazard on Wednesday.
Most defenders can ill-afford to lose their opponents at the best of times, and when that man is Chelsea's Hazard, it undoubtedly spells trouble. On Sunday, Gibbs ghosted beyond Tiendalli all too easily to latch onto Olivier Giroud's through ball, but Hazard will pose an altogether more difficult challenge for the Swansea man.
The young Belgian's exceptional movement makes it difficult for his marker to track him, but when in possession, he is even more deadly. He has six goals to his name thus far this season, but has created an incredible 13 for his teammates, outlining just how pivotal he is to the Blues' attack.
With Ashley Cole looking to get forward and support Hazard at every opportunity, Tiendalli will need to be on his toes—otherwise Chelsea could put this tie beyond Swansea after the first 90 minutes.
With Danny Graham back scoring, Swansea are an even bigger threat going forward
It's not often Chelsea's Branislav Ivanovic loses one of his personal battles on the football field, but a rejuvenated Danny Graham will give him plenty to think about at Stamford Bridge.
The Swansea hitman has found the back of the net in his last three outings, including the equaliser against Arsenal at the weekend. That strike, coming in the 87th minute to make it 2-2 and earn a replay, was a stark reminder of why he came so highly rated when former manager Brendan Rodgers snapped him up from Watford in the summer of 2011.
It may have taken Michael Laudrup a little longer to realise it, but the former Middlesbrough man is a major threat in the box and with most defences wary of his teammate Michu, Graham has grabbed his opportunity to impress of late and will be hoping to become a regular once more.
Ivanovic is a tough customer, though, and in the absence of John Terry due to injury, is beginning to form an excellent partnership with Gary Cahill in central defence.
Graham will need to be physical and elusive if he's to outplay Ivanovic, but as so many have found before him, sometimes even that isn't enough against the Serbian.
Juan Mata is Chelsea's talisman going forward
Swansea's Jonathan de Guzman has proved adept at scoring goals from midfield since arriving on loan from Villarreal. However, he will need to prove just as useful at preventing them if his team are to have any chance against Chelsea on Wednesday.
Alongside Leon Britton, he will be charged with preventing Juan Mata from doing what he does best—creating havoc in the middle of park.
It's a key battleground that Southampton found to their detriment on Saturday, as Mata played his part in unlocking the Saints' defence to help the Blues record an emphatic 5-1 victory and advance into the fourth round of the FA Cup.
Chelsea looked strong going forward, unrecognizable when compared with the team that fell to a 1-0 home defeat at the hands of bottom club QPR just three days previous. Mata wasn't playing that night, and it didn't take a great footballing mind to see his influence was missed.
With their talisman expected to maintain his place in the starting XI against Swansea, a repeat performance of the Southampton victory is expected.
But one suspects De Guzman will have something to say about that.