The two enemies meet again: Swansea City and Arsenal.
It doesn't immediately make sense why a matchup between these two teams is so intriguing and such an entertaining fixture. But a look at the clubs' games against each other during the last two seasons tells the story.
Arsenal have won only one of the three matches that they've played against Swansea since the Swans were promoted at the start of the 2011-12 season.
That came way back in September 2011 at the Emirates Stadium, with the Welsh side still getting used to life in the Premier League and Arsenal looking for vengeance after their infamous 8-2 shellacking at the hands of Manchester United.
Since then, it has been an entirely different story.
Almost a year ago, in the throes of an awful injury crisis, Swansea beat Arsenal by the score of 3-2 at home. But the Swans' one-goal margin of victory belied one of the greatest attacking performances of last season's Premier League.
On that day, one could legitimately compare Swansea to Barcelona, such was their ruthless pressing in all areas of the pitch, their crisp laser-like passing and their consistently intelligent movement.
Robin van Persie got an early goal that day and Theo Walcott bagged a flukey equalizer in the second half, but Arsenal were mercilessly run off the pitch.
The same outcome recurred when the two sides met on December 1st. The Gunners were never able to establish a foothold in the game, and two late Michu goals sunk the home side in embarrassing fashion.
Why does Swansea, a supposedly inferior team, dominate Arsenal so?
Put simply, they outplay the Gunners at their own game.
It is a bit of a cliche—and not an entirely true one, at that—but Arsenal are a bit like Barcelona-lite. They attempt to beat an opponent not with long balls, but with measured buildup engineered by technically gifted players that actively press to win the ball back.
Swansea play that style too. Bred under Brendan Rodgers and nurtured this season under Michael Laudrup, the Swans never stop pressing to win the ball back when they've lost it, and tend to keep it for the majority of matches.
Though they do not have the sorts of names in their squad that Arsenal do, a cheaply assembled, often vastly underrated cast of characters can do all the dirty work with the flair of a Champions League side when it's their day.
Regarding team news, both sides are relatively clean. Both sides might choose to rest tired legs, but there are no new injury concerns for either side.
Arsenal have Abou Diaby and Andre Santos returning to training, but it's likely that neither will be match-fit by game time on Sunday. Lukasz Fabianski is a long-term absentee and Vito Mannone is sick, so Damian Martinez will likely deputize for Wojciech Szczesny.
It's always difficult to project lineups for cup ties, especially when each club has multiple other matches before and after.
Some managers feel that this could be their year to have a go at a trophy, while others need to focus all their resources on the Premier League, leaving no excuses for not taking as many points as possible.
To be relatively safe, we'll assume that both Arsene Wenger and Michael Laudrup will make some moderate changes to their teams that played on New Year's Day.
Here's how Swansea could line up: Michel Vorm; Chico, Ashley Williams, Dwight Tiendalli, Angel Rangel; Leon Britton, Kemy Agustien, Jonathan de Guzman; Nathan Dyer, Wayne Routledge, Michu.
And Arsenal's potential counter: Wojciech Szczesny; Carl Jenkinson, Per Mertesacker, Thomas Vermaelen, Kieran Gibbs; Mikel Arteta, Francis Coquelin, Tomas Rosicky; Lukas Podolski, Gervinho, Olivier Giroud.
For neutrals or fans of either club, this will be a tremendously exciting fixture if the last two matchups are any indication.
Remember that I will have live blog coverage of the game, starting nice and early at 8:00 am ET on Sunday.