The 20th season of Major League Soccer is scheduled to start Friday, and with it, the start of eight-year television deals with Fox, ESPN and Univision worth $90 million a year.

The league’s new expansion teams, Orlando City and New York City F.C., are to face off Sunday on ESPN2 in front of more than 60,000 fans at the sold-out Citrus Bowl.

But all that good news might get buried, for at least a little while, if M.L.S. players go on strike over free agency and higher salaries. The players’ union and the league have been negotiating a new collective bargaining agreement for weeks, and have been in talks with the aid of a federal mediator since Sunday in Washington. But a strike could be called as early as Wednesday to keep the teams that are scheduled to play Friday from traveling to game sites that would be shuttered.

No side looks good when a season is delayed or interrupted by a labor stoppage. Players, especially those at the bottom of M.L.S.’s modest payrolls, could struggle without their salaries. The league’s wealthy owner-investors will save the expense of paying players for a while, but will absorb the brunt of the criticism for appearing miserly. But work stoppages have become a labor tradition in sports: players fighting for better pay and freedom of movement, and leagues trying to preserve their profit margins while maintaining the status quo — most notably in baseball with the former commissioner Bowie Kuhn’s love of the indentured servitude of the reserve clause.