(Bloomberg) -- Footballers are getting injured more frequently across Europe’s top divisions, according to research from an international insurance broker, as the sport prepares for a period of intense fixture congestion.

The number of injuries in Europe’s five biggest leagues rose 20% last season compared with a year earlier, an index compiled by Howden said. There were 4,810 instances of players being out for more than a day, with the English Premier League experiencing the most injuries (1,231). Chelsea was the worst-affected English club, with 97 injuries.

The cost to clubs, calculated by adding the base salaries of players on each of the days they were injured, climbed 29% to reach £513 million ($547 million) -- exceeding the half-a-billion pound mark for the first time.

Concern about injuries is a constant refrain from teams’ managers as more games are demanded of players in a crowded calendar. This year’s fixtures are being unusually disrupted by a World Cup staged in November and December, while in England a round of games was postponed following the death of Queen Elizabeth II. 

Some top English teams are scheduled to play nine matches in October.

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English clubs suffered the greatest cost from injures last season, according to the index, at £184.6 million with Spain’s La Liga in second place. France’s PSG reported the highest injury cost for a club, followed by Real Madrid and then Barcelona.

“This research confirms what leading club managers have been saying for a while now -- injuries are on the rise across European football,” said James Burrows, head of sport at Howden.

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