Fifa's expanded Club World Cup in the United States has reached the end of its group phase, with two weeks of knockout matches to come.

Having risen from seven teams to 32, the competition has received criticism over player welfare concerns with matches played in extreme temperatures, often with poor attendances.

Critics say the Club World Cup is purely there to boost Fifa's finances, while football's governing body argues the event is needed to build up to next summer's five-week World Cup, which will feature 48 nations and be held in 16 cities across Canada, the US and Mexico.

This has been a competition of massive contrasts. From hugely one-sided thrashings, such as Bayern Munich setting a new tournament record when they crushed New Zealand part-timers Auckland City 10-0, to thrilling matches, including 4-4 and 4-3 scorelines.

We have taken a look at five talking points so far.

Ever since the tournament expansion was announced, there have been major concerns over the workload of the players, especially with the World Cup coming up in 12 months.

Since the main European seasons began in August, Real Madrid have now played 65 times, Inter Milan 62, Paris St-Germain 61 and both Chelsea and Manchester City 60 apiece, with four more games to come if they reach the final.

What has made it worse is the temperatures the matches are being held in. Temperatures reached 36C during the game between Bayern Munich and Benfica in Charlotte, North Carolina, while Chelsea manager Enzo Maresca said it was "impossible" to organise normal training sessions amid a "code red" severe heat warning in Philadelphia.

Cooling breaks have been used with players dashing to get some shade, often while wearing an ice-cold towel or throwing bottles of water over their heads in an attempt to cool down.

The threat of thunderstorms has caused lengthy delays to five matches because play in American stadiums has to be halted when lightning is recorded within a 10-mile radius.

With three venues in Mexico, as well as cities including San Francisco, Los Angeles, Dallas, Houston, Atlanta and Miami hosting matches in the 2026 World Cup, weather delays could well be a feature of that tournament as well.

There have been crowds of more than 40,000 at 18 of the 48 group games with numerous superb atmospheres.

The highest attendance so far has been the 80,619 that watched European champions Paris St-Germain thrash Atletico Madrid 4-0 at the Rose Bowl in Pasadena.

Top 10 attendances of the Club World Cup

However, many games have not sold as well, with nearly 50,000 seats left unfilled for Chelsea's opener against Los Angeles FC in Atlanta.

Eight of the 10 lowest attendances have come from matches played between Monday and Friday and six of those 10 started between midday and 3pm local time with Fifa struggling to balance the local demand for tickets, tournament prices and scheduling matches to satisfy the lucrative television markets in Europe and Asia.

Worst 10 attendances of the Club World Cup

"I wouldn't imagine an NBA court full of holes," the 55-year-old said after his side beat Seattle Sounders 2-0.

"What I really care about is the state of the field of play. The ball bounces almost like if it were jumping around like a rabbit."

Real Madrid's Jude Bellingham also found fault with the pitch following his team's 3-1 victory over Pachuca.

"The pitches aren't great at all. It holds up the ball, the ball barely bounces," said the England midfielder. "It's tough on the knees as well. Hopefully there's someone who will look at that going into the World Cup next year."

In short, very seriously. But then that is understandable considering there is a £775m prize pot, which will be split between the 32 teams, with the winners earning up to £97m.

Clubs will take home a set figure for each round they reach. A win in the group stage earns them £1.5m, a draw £800,000, while they get an additional £5.8m for reaching the last 16, another £10.1m for getting to the quarter-finals, £16.2m for making the semi-finals, £23.2m for being in the final and £30m for winning the whole thing.

Manchester City were the only team to win all three of their group matches, beating Moroccan side Wydad AC 2-0, Al Ain of the United Arab Emirates 6-0 and then Italy's Juventus 5-2 on Thursday.

Before the tournament started, football data specialists Opta said the 11 most likely teams to win the trophy were all from Europe.

However, three of the continent's 12 sides have gone out in the opening phase with Porto, Atletico Madrid and Red Bull Salzburg all exiting after finishing third in their respective groups.

There were six sides from South America and while both of those from Argentina have been eliminated, all four from Brazil have made it through with Palmeiras taking on Botafogo in a last-16 tie.

Two of the five teams from North America - Inter Miami and Mexico's Monterrey - are still going, while Saudi Arabian outfit Al Hilal, who play Manchester City in the first knockout round, are the only Asian side left in.

All four African teams failed to make it out of their groups, as did Oceania's only representative Auckland City, although the part-timers did gain a memorable 1-1 draw with Boca Juniors of Argentina.

Last 16 fixtures (all times BST)

The quarter-finals will be played across 4 and 5 July, the semi-finals on 8 and 9 July, with the final taking place on 13 July.

At the conclusion of the group stages, there's a five-way tie in the race to become the tournament's top scorer.

Bayern Munich duo Michael Olise and Jamal Muisala both have three goals, with the latter scoring a hat-trick in the German side's 10-0 win against Auckland on the opening day of the tournament.

Former Manchester United winger Angel Di Maria, 37, scored twice for Benfica in a 6-0 win against the Kiwis, as well as another in a 2-2 draw against Boca Juniors.

Juventus playmaker Kenan Yildiz, 20, has been the standout performer so far for the Italians, scoring three times in his three appearances in the United States.

Al Ahly forward Wessam Abou Ali is the surprise inclusion in the race, with the 26-year-old netting a hat-trick in his side's 4-4 draw with Porto in the final group stage but with his side eliminated, the striker will be unable to add to his tally.