The world's top men's doubles players are to take their grievances over planned rule changes to court.
The Bryan twins are supporting the legal action
A complaint against the ATP, men's tennis' governing body, was filed at a federal court in Houston.
The players are seeking an injuncton to stop the ATP from implementing the changes, which would include shortening matches and amending qualifying rules.
"If we don't unite, there might not be a game of doubles," said Mike Bryan, one of the world's top doubles players.
"Our backs are against the wall," added Bryan, a specialist in the two-man game alongside twin brother Bob.
Under the new ATP scheme, players would have to qualify for the singles tournament to be eligible to compete in doubles events.
ATP DOUBLES PLANS
Sets first to five, with tie-break at 4-4, "no ad" games
More matches scheduled on show courts
Qualification based on combined ranking of half singles and half doubles points
Sets would be abbreviated to the first to five games, with no breaks at the changeover and a sudden-death point at deuce.
More than 20 top doubles players, including world number one Jonas Bjorkman, attended a news conference before the start of Friday's play at the US Open.
Players' lawyer John Sullivan said: "We are not seeking any monetary damages.
"All we want is the ATP to assume responsibility they should have before and change the rules back and protect the game of doubles."
The scoring changes will be tested in six tournaments beginning the week after the US Open, while the new qualifying system is planned for 2008.
ATP spokesman David Higdon said: "I hope everyone can step aside and we can talk together and grow the game.
"These changes are experimental. They are definitely not set in stone."