As labor negotiations go, the current impasse in Major League Soccer has been kitten play to this point. No one could have reasonably described the proverbial air in the room as “heated” or “contentious.”

It was difficult to even sense a genuine threat of delaying this week’s important season openers around MLS. Sides had generally expressed guarded optimism that a new CBA would arrive in due course.

Signs began arriving Tuesday of a change for the worse. For the first time, games this weekend seem in actual peril, which would represent the first work stoppage in Major League Soccer’s 20 years.

Snippets of proposals and further signs of entrenched stances began to leak Tuesday as talks continued in Washington, D.C., where a federal mediator is assisting as negotiators for Major League Soccer Players Union and the league attempt to work out the latest collective bargaining agreement. Sides worked last week to get all the little things out of the way so that everyone could focus intently on the primary obstacles – increases in the minimum player salary and, most critically, the players’ dogged push toward free agency.

The looming pressure point here is Friday as the league’s milepost 20th season is set to kick off; Chicago visits the reigning MLS Cup title holders L.A. Galaxy. Adding more to the stakes, that is also the first national TV game (on UniMas) in a new package of English and Spanish-language broadcasts that will pay the league about $90 million annually, a substantial increase over past national television deals.

All 20 teams, including high profile debuting expansion clubs in Orlando and New York City, have matches scheduled for Friday, Saturday or Sunday.

No question that permitting progress toward free agency, with the added entanglements of how it affects the league’s bedrock single-entity ownership structure, remains the mighty hurdle toward labor accord. Players want more than the tiny steps toward unlimited free agency won in 2010 during the last CBA negotiations (a cumbersome re-entry draft system for players out of contract). But league owners are heavily invested in preventing any such movement. Real Salt Lake owner Dell Loy Hansen last week told Salt Lake City’s ESPN Radio affiliate that discussions on free agency were a “a go-nowhere conversation.” (Hansen’s comments earned him a fine from commissioner Don Garber, according to Sports Illustrated.)

Some player reps have now arrived in Washington. According to The Oregonian’s Jamie Goldberg, Portland Timbers players Nat Borchers, Jack Jewsbury and Will Johnson flew east on Tuesday to participate in the ongoing talks. That could indicate that something is happening, although only those in the room know whether that “something” is a strike vote or a move toward a ratification vote.

According to Vancouver-based reporter Cam Tucker’s Twitter feed, Whitecaps player representative Steve Beitashour said “a strike vote would occur either tonight [Tuesday] or tomorrow morning.” That doesn’t absolutely mean a strike is forthcoming, of course; it’s a vote. But even a vote, if it happens, represents a fairly serious escalation from the players’ side.

Washington Post veteran reporter Steven Goff reported that owners have proposed that players age 32, with 10 years’ at the same MLS club, may become free agents. (That represents precious few players.) Goff also reported that the Chicago Fire may cancel travel plans to Los Angeles, scheduled for Wednesday, without signs of further progress.

There are two possibilities here:

One, that MLS players are seriously digging in and actually considering putting the “strike card” into play.

The other possibility here is that nothing has really changed – except that leaders on either side are now reacting to the pressure of looming MLS openers. If one side senses slipping leverage or is beginning to get nervous about things, taking the fight public may be nothing more than the next chapter in the tactical field manual.

As writer Kyle McCarthy mentioned via Twitter: “Everything – every single word inside and outside the room – is tactical at this stage of a negotiation.”

In 2010, amid a backdrop of rhetoric stronger than what we’ve heard this time around, a new CBA was agreed upon by both sides six days before the season opener.

Editor’s note: Steve Davis writes a weekly column for World Soccer Talk. He shares his thoughts and opinions on US and MLS soccer topics every Wednesday, as well as news reports throughout the week. You can follow Steve on Twitter at @stevedavis90. Plus, read Steve’s other columns on World Soccer Talk