The 138th final of the FA Cup, the world's oldest club competition, pits all-star Premier League champions Manchester City against able underdogs Watford.

The odds may be heavily stacked in favour of Pep Guardiola's team, but there is enough cause to believe that Javi Gracia can mastermind a memorable upset that would be a fitting conclusion to what has been a thrilling tournament this season. Here's everything you need to know.

WHERE: Wembley Stadium, London (capacity 90,000)
WHEN: Saturday; noon ET, 5 p.m. UK (live on ESPN+)

BACKSTORY: This is Watford's second FA Cup final (35 years ago, they lost 2-0 to Everton) and for most of their history they've been a second-tier club, though since their most recent promotion to the Premier League in 2015 they've generally been solidly mid-table, finishing 11th this season.

Manchester City are arguably the best team in the world right now and, in English terms, have completed the most dominant two seasons ever, having gained 198 of a possible 228 in winning back-to-back titles. They retained the Carabao Cup this year and would complete an unprecedented domestic treble if they win this too.

MUSICAL ICON: Oasis' Noel Gallagher is a fixture at City games, and he led the title celebrations in the dressing room at Brighton. But Elton John has him trumped, despite having to miss the match to perform a concert in Copenhagen, Denmark. He was actually chairman of Watford on two occasions for a total of 16 years. Plus, his middle name is Hercules, whereas Gallagher's is a more mundane Thomas.

The @oasis classics were in full flow as @ManCity celebrated back-to-back @premierleague titles ? pic.twitter.com/gpA6sgFyx6

— ESPN UK (@ESPNUK) May 13, 2019

ROAD TO WEMBLEY: The FA Cup is a straight knockout competition, so luck and happenstance play a key role, especially since the rounds are one-legged: you only play the return leg if it's a draw through to the fourth round. City won all five of their games on the way to the final, but faced just two Premier League clubs (Burnley and Brighton) en route. Watford faced three top-flight clubs on the way (Crystal Palace, Newcastle United and Wolverhampton Wanderers) and only played at home once.

KEY COMEBACKS ON THE WAY: Watford had to come from two goals down in the semifinal to overcome Wolves 3-2 in extra time. Manchester City found themselves 2-0 down with 21 minutes to go away to second-tier Swansea in what would have been one of the shocks of the season. But they stormed back and grabbed a winner with two minutes to go, sealing a 3-2 victory.

KEY BATTLE: Abdoulaye Doucoure and Etienne Capoue vs. the Silva brothers

OK, the latter aren't actually brothers, they just have a chemistry and understanding that suggests either blood relations or extra-sensory perception. If City, as expected, have the bulk of possession and Watford raise the barricades, it will be up to Bernardo Silva and David Silva (or possibly Ilkay Gundogan, Kevin De Bruyne or Phil Foden -- yes, City have that many weapons) to break them down. Capoue and Doucoure form one of the best midfield duos in the Premier League, offering physicality, workrate and tactical nous. If City can't get through them, they'll need to figure out a way around them.

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X FACTOR, WATFORD: Gerard Deulofeu

He doesn't always start, but he has the unpredictability and one-on-one ability to create something out of nothing and, of course, his heroics in this very stadium in the semifinal are what got Watford here.

X FACTOR, MANCHESTER CITY: Leroy Sane

The fact that you can chuck the German roadrunner on the pitch late in games, against tired, glassy-eyed opponents is a huge boost. He gets in the box with the ball with an ease rarely seen at this level.

HEART AND SOUL, WATFORD: Troy Deeney

It's the ninth season at the club for this battering ram of a striker who leaves nothing on the pitch and has worked under 11 different managers. Not always the prettiest to watch, but his effort and underdog redemption story -- he spent time in prison for his involvement in a brawl when he was 22 and later passed the equivalent of a GED (General Educational Development) exam -- make him appealing to neutrals.

HEART AND SOUL, CITY: Raheem Sterling

His is also a redemption tale, though more a factor of how he was perceived rather than anything he did. Cruelly and unfairly lampooned as greedy and bling-obsessed when he moved from Liverpool to Manchester City, he is now adored in England and has established himself as a thoughtful commentator on social issues as well. At 24, his star is still rising ...

OLD TIMER, WATFORD: Heurelho Gomes

He's 38, he's no longer a regular, and he's meant to be leaving at the end of the season, even though Watford have asked him to stay another year. But he's immensely popular at the club and the chief cheerleader, whether he starts or not. Definitely one of the good guys.

OLD TIMER, MANCHESTER CITY: Vincent Kompany

He's been here for 11 years, pre-dating the Emirati owners and the transformation of Manchester City into a super-club. Once one of the best defenders in the world, he was slowed by injuries the past three years only to come roaring back this season with some vintage performances (and an improbable key goal against Leicester City) down the stretch. Articulate, bright and a natural leader, when (if?) he leaves then he can pretty much write his own ticket whatever he chooses to do.

WHAT WATFORD HAVE TO DO TO WIN IT: Impose themselves physically in midfield with the Doucoure-Capoue partnership. If, as expected, Gracia opts for two strikers, ensure that they pin back City's full-backs when not in possession and disrupt the build-up as much as possible. Exploit the size advantage on set pieces.

WHAT CITY HAVE TO DO TO WIN IT: Let their superior talent and know-how shine and carry them to victory. Do not get frustrated if the goals take time to come. Drop Sterling into central positions to wreak havoc if Watford pack the penalty box. Dominate the wide areas to stretch the opposition and create gaps for the midfield to exploit.

PREDICTION: Manchester City to win 3-1

It's a combination of nous and firepower. Watford can be very awkward to play against, so if things don't pan out early for City boss Guardiola he may need to find other solutions. Luckily for him, he has a whole array of options to call upon, either from the bench or simply by switching players around.