"The sector has been looking shaky for a while and with the amount of new space being added, any slackening of demand is bound to affect profitability," one analyst said. Clive Vaughan of Verdict retail consultants agreed, saying: "This does look a bit like a bubble that is very close to bursting. There is nervousness out there at the moment and though we can see consumer demand growing, the amount of new space the retailers are adding can only end in tears."
There were suggestions late last week that some of the sports chains are suffering double-digit declines in like for like sales. It is understood that trading was particularly weak in February but may have picked up in March.
It is now almost certain that Sports Division, the privately-owned sports retailer, will postpone its pounds 350m stock market flotation which had been planned for the spring. A final decision will be made after JJB Sports reports its full year results on 22 April.
Investor confidence has been shaken by a series of negative announcements from the sector in the last six weeks. Nike issued a profits warning in March after problems in the US and the Far East. Also last month the former merchandising director of Manchester United said the boom in replica football shirts may be over. Newcastle United added to the woes when some of its directors were alleged to have made comments about replica shirts being over-priced.
A bigger concern is the possibility of a shift in fashion tastes. The popularity of training shoes has been affected by the rise of the "brown shoe" market which includes brands like Timberland, Rockport and Caterpillar. Even the previously un-trendy Clarks shoes have been popularised by rock bands such as Oasis and The Verve, who wear the company's desert boots and Wallabees shoes.
There is also evidence that more formal clothing may be rising in popularity at the expense of heavily branded sportswear. At the company's results last week, Rowland Gee, managing director of Moss Bros, the menswear retailer said: "It is Adios Adidas. People just don't think it is as trendy to wear sports labels for fashion any more."
Verdict's Mr Vaughan agrees that in the same age groups, a Ben Sherman shirt is more likely to be the new "must have" fashion item. He warns that companies such as Nike are sitting on mountains of unsold stock and the fashion appeal of owning a pair of its trainers will be eroded if stores are forced to reduce prices. "The whole point of these brands is that they supposed to be aspirational. If suddenly an pounds 80 pair of Nike trainers is remaindered down to a tenner, street-wise young kids won't buy them."
He says that after years of ignoring traditional shoe shops, the top brands like Nike have started to "knock on their doors" asking if they would like to start stocking their goods.
The appeal of these brands is also being under-mined by supermarket groups selling sports clothing and trainers at cut prices after securing supplies on the "grey market". Tesco has cut the price of Levi's jeans and Nike trainers in recent months. It is selling Tommy Hilfiger clothing at reduced rates, including a T-shirt for pounds 15 which it said was pounds 25 in Selfridges.
Tesco says it is not planning to enter the sports market but is securing the supplies as part of its campaign against selective distribution. Brands like Levi's and Nike have refused to supply supermarkets saying their store environments and lack of specialist staff makes them unsuitable outlets.
However, it would be premature to write the sports brands off completely. They are backed by huge advertising campaigns and replica shirts are unlikely to fall out of favour dramatically given the rising popularity of football and the continued backing of Sky TV.
And then there is France '98 in June. As Mr Vaughan of Verdict says: "There has been a bit of slippage in the market but we still have the World Cup to come and marketing for that has not even started yet."
For the sports retailers, a strong World Cup challenge by England, or even a sustained run by Scotland, would be seen as the hand of God.