A study by the Football Association found these injuries force players to miss an average of 22 days during the season.

The total cost to English clubs is estimated at almost �75m each year.

The better a player maintains his fitness level during the off season, the lower the risk of overuse injury during the preseason

Dr Thor Andersen

Researchers at the FA called for a review of training methods to prevent players from picking up injuries.

Caroline Woods and colleagues at the FA's medical and exercise science department analysed pre-season injuries among players from 91 English clubs over two years.

Minor injuries

They found nearly a fifth of all injuries were sustained before the season got under way.

Players under the age of 25 were most likely to have problems.

About 40% of the injuries were minor. They included muscle and ligament strains, thigh injuries and Achilles problems.

Minor injuries were higher pre-season than during season. The researchers suggested that this was because of tough training programmes.

Writing in the British Journal of Sports Medicine, they urged clubs to review their pre-season training programmes.

They said clubs should ensure pitches are well-watered to reduce the strain on players.

They also suggested that managers should consider alternatives to heavy running such as training in swimming pools.

Help themselves

But the researchers added that players themselves could take action to reduce their risk of getting injured.

They suggested that players should try to keep their fitness levels up when the season ends so that pre-season training is not too much of a shock to the system.

In addition, they urged players to make sure new football boots fit well and are comfortable before they start intensive training.

They said players should also make sure they are fully recovered from any injuries before they start training.

"The likelihood of a pre-season injury predisposing players to injury later in the season emphasises the importance of adequate and complete rehabilitation of pre-season injuries especially slight and minor injuries," the researchers said.

Staying fit

In an accompanying editorial, Dr Thor Andersen of the Norwegian University of Sport and Physical Education backed the FA's conclusions.

"During the pre-season there is a large increase in training load, particularly for players who do little or no conditioning in the off season.

"Abrupt changes in training volume and intensity are assumed to be a major risk factor for overuse injuries."

They added: "It seems safe to assume that the better a player maintains his fitness level during the off season, the lower the risk of overuse injury during the pre-season."