What's red on the outside but has an obvious black-and-white tinge when you look a little more closely? Answer: the still developing Liverpool team being put together by Brendan Rodgers.
Neither clash is quite as big as it would have been in recent seasons, simply because Arsenal (who are sixth in the table) and eighth-placed Liverpool are performing below the level expected of them.
In Liverpool's case, the reason why they have been unable to take a higher position is clear from their form lines. While his team have won eight out of 11 against teams in the bottom half of the table, Rodgers has yet to engineer a victory over any team in the top half. Liverpool's best win was the 3-2 success at 11th-placed West Ham in early December.
By contrast, in terms of points per game, only the two Manchester clubs have performed better than Liverpool against bottom-half teams - a ranking in which the big six fill the top six places. Liverpool's average of 2.36 (against United's 2.75 and City's 2.55) would put them in the thick of the battle for a Champions League place if it wasn't for their abysmal form against top-half teams.
In that category Liverpool rank 16th and the depth of their under-achievement is evident in the fact that only the bottom four overall (Reading, QPR, Wigan and Southampton) have done worse. Southampton are the only team apart from Liverpool who have failed to beat a top-half opponent.
All of which does not bode well for Liverpool's chance at Manchester United, especially as they have failed to keep a clean sheet in seven games against teams above them in the table. United's record when scoring at home is superb - 42 wins out of 48 in the Premier League in the years since Cristiano Ronaldo's departure.
Liverpool have not kept a clean sheet on their last nine visits to Old Trafford in league and cup and they have lost eight of those games - the only exception was the 4-1 league win in 2009 when they pushed United all the way for the title.
With their current form nowhere near that level, Liverpool will have to improve markedly to live with United on Sunday. At [1.9] to back, United look a good bet for the win.
An even better bet, according to my ratings, is Manchester City off scratch at [1.98] on the Asian handicap for their trip to Arsenal.
The Asian handicap option covers the possibility of a draw, which is worth having as the only weakness in City's away form is that their win rate is too low for a side with title ambitions.
City have won five out of 10 on the road (50%) while United have won eight out of 11 (73%), which essentially accounts for the points gap between the two title chasers.
Yet City's away form is poor only in comparison with United's - they are unbeaten in three visits to top-eight teams and have lost only one of their last 13 away games in the Premier League.
Arsenal's home form is up and down but the key statistic might be that, like Liverpool, they seem unlikely to win without a clean sheet.
City have lost only once in 21 games when scoring on the road in the Premier League since the start of last season, with 15 wins. Five of Arsenal's seven clean sheets this season have been against teams in the bottom seven and they have won only one out of five when conceding against top-half teams.