The new year begins with a bang in world soccer. There are big games in England and Spain, the biggest rivalry in the Americas, and the returns to action of Germany’s Bundesliga and Italy’s Serie A.

But the most fascinating story of the weekend involves a former Union castoff who played barely half of the team’s inaugural season, and is now the hottest coach in La Liga. Yes, really.

Manchester United vs. Aston Villa

Friday, 3 p.m. (NBCSN)

Here are the words that United fans have longed to read: A win would send Marcus Rashford and the Red Devils into a tie for first place with Liverpool. Jack Grealish’s Villa is in fifth, and a win could push it as high as third. But all the attention will be on United, which hasn’t topped the table since September 2017.

» READ MORE: This weekend's Premier League schedule

Werder Bremen vs. Union Berlin

Saturday, 9:30 a.m. (ESPN+)

2021 has the potential to be a landmark year for Bremen’s Josh Sargent. The 20-year-old U.S. national team striker has finally locked down a starting role for his club and is No. 2 on the team in chances created per game. Unfortunately, he’s scored just three goals this season, but then again no one on 13th-place Bremen has scored much. If he keeps playing well, he’ll give the U.S. a big boost in a year full of big games.

Real Betis vs. Sevilla

Saturday, 10:15 a.m. (beIN Sports, beIN Sports Español)

The Seville derby is one of Spain’s fiercest rivalry games, even though it doesn’t get as big a spotlight as the ones in Madrid and Barcelona. Sevilla has dominated in recent years, but this Betis squad is pretty good.

Betis’ big names include French playmaker Nabil Fekir, Spanish winger Cristian Tello, and Mexican national team stars Andres Guardado and Diego Lainez. Sevilla counters with Argentine winger Lucas Ocampos and Croatian playmaker Ivan Rakitic, a former teammate of Tello’s at Barcelona.

» READ MORE: This weekend's La Liga schedule

Real Madrid vs. Celta de Vigo

Saturday, 3 p.m. (beIN Sports, beIN Sports Español)

If you’ve been a Union fan since the beginning, you might remember Eduardo Coudet. Or you might not, because he only spent half a year here and played just nine games. But it was long enough for the Sons of Ben to draw up a chant for him: “Chacho Man,” to the tune of the Village People classic “Macho Man.”

Coudet played one more year after the Union waived him, with the now-defunct NASL’s Fort Lauderdale Strikers. Then he went into coaching. He’s had stops in Argentina, Mexico and Brazil, and now is in charge of Spain’s Celta de Vigo.

Now Coudet is in one of the biggest leagues in the world, and he’s an incredible success story. Since he took over Celta on Nov. 21, the team has won seven of nine games and tied another. No other team in La Liga has scored more or conceded fewer goals in that stretch.

Going up against Real Madrid, coached by Zinedine Zidane, is big enough on its own for Coudet. But Celta’s hot streak makes the game even bigger.

» READ MORE: Union to sell Mark McKenzie to Belgium’s KRC Genk for $6 million-plus

Boca Juniors vs. River Plate

Saturday, 7:30 p.m. (TyC Sports Internacional)

This one will be hard to find, because TyC isn’t widely available. DirecTV and Verizon FiOS carry it on premium tiers, and it’s on subscription streaming platforms FuboTV and Fanatiz. But if you can find a way to watch, do it. Boca-River is the biggest, fiercest, loudest — well, not during a pandemic — rivalry in all of the Americas, and one of the most famous in the world.

Borussia Dortmund vs. VfL Wolfsburg

Sunday, 9:30 a.m. (ESPN+)

As ever there are no guarantees, but this game should see Americans Gio Reyna play for Dortmund and John Brooks play for Wolfsburg. It’s also a big game in the standings as fifth-place Dortmund trails fourth-place Wolfsburg by two points.

» READ MORE: This weekend's Bundesliga schedule

Chelsea vs. Manchester City

Sunday, 11:30 a.m. (NBCSN, Telemundo)

The headline for most viewers is Chelsea being in sixth place, and Manchester City being in eighth, instead of the loftier heights they’re used to. But there’s a special storyline for soccer fans around here. It could be Downingtown-bred Zack Steffen’s first Premier League start, and it could come against Hershey’s Christian Pulisic.

Unfortunately, Steffen’s chance comes in negative circumstances. A COVID-19 outbreak in City’s ranks has sidelined a number of players, including starting goalkeeper Ederson. We don’t know if Ederson has tested positive, but he said on his Instagram account that he is isolating.

If Steffen and Pulisic get the respective calls, it will be the first time that two Philadelphia-area natives share a field in the English Premier League. You can be sure NBC Sports — which has its own ties to Philadelphia, being owned by Comcast — will make it a big deal, and rightly so.

» READ MORE: Zack Steffen has it all at Manchester City, except the one thing he needs most

Juventus vs. Udinese

Sunday, 2:45 p.m. (ESPN+)

All 20 teams in Serie A return to action on Sunday, and it’s no surprise that Italy’s biggest team plays in the last game of the day. Weston McKennie, Cristiano Ronaldo and company start 2021 in sixth place in the standings, 10 points back of first-place Milan. The bianconeri have lost just once this season — a 3-0 rout at old rival Fiorentina on Dec. 22 — but have tied six of their 13 games so far.

» READ MORE: This weekend's Serie A schedule