NEW YORK (CNNMoney.com) - With Barry Bonds bearing down on Babe Ruth's home run mark, it seems every sportswriter and baseball fan is concerned about the sanctity of baseball's records due to Bonds' alleged use of steroids.

But getting a lot less attention is a threat to something that's more important: the damage being done to labor-management relations.

Baseball's probe into possible use of steroids by slugger Barry Bonds could hurt labor peace in the sport.

There's plenty of reasons for players to distrust former Sen. George Mitchell's steroids probe, despite his strong reputation.

The current collective bargaining agreement is set to expire after the end of this season. So we could be soon be back to the bad old days of lockout and strike or worse -- actual work stoppages. Here's why.

Last week, a union lawyer sent a memo to all players agents laying out the problems that the union leadership has with a steroids investigation being led by former Sen. George Mitchell. Reports of this memo were first published in Newsday.

The memo charges that Mitchell's investigation, announced in March, is "a substantial disruption to our ongoing bargaining relationship" and also claims that Mitchell is requesting medical and phone records of current and former players, a move that the union says violates the rights of its members.

Kenneth Shropshire, a professor at the Wharton School of the University of Pennsylvania and an expert on both sports business and negotiations, said the steroid probe seems to be stirring union distrust of the owners on the core issue of players' privacy rights. That could make it more difficult to hammer out a new labor deal.

Still, he expects the two sides to reach a deal without an actual work stoppage this time.

David Carter, executive director of USC's Sports Business Institute, said he also expects a deal without games being lost next season, but he also thinks that the steroids issue could stir up more fan anger if the union starts talking about things like strike deadlines.

"You can't get to an overall agreement until you reach an agreement on steroid peace," he said. "Will [steroids] stir up negotiations? Absolutely. The question is to what extent does the Mitchell investigation undermine improving labor relations?"

Ironically, the current steroids testing program could be among the first victims of a dispute.

Congressman Tom Davis, one of those on Capitol Hill who pushed the owners and union to strengthen steroid testing, brought to light this week a little known provision in the current program. Both sides need to agree to terms of the testing program by August 1, or else the union can pull the plug on it and reinstitute a much less stringent one that was in effect in 2005.

The union will be the one taking the public relations hit in all of this, of course. But even though sportswriters generally trumpeted the commissioner's description of Mitchell as "one of the most respected public figures in the nation," there is plenty of reason for players to distrust him.

Mitchell was on the so-called "Blue Ribbon Committee" that portrayed both the state of finances and competitive balance in the game as dire ahead of the 2001 labor negotiations. The report did little but argue the owners' negotiating point of view. The game's success since then brings into question how true that point of view was then.

Mitchell also is chairman of Walt Disney Co. (Research), parent of baseball broadcast partner ESPN. And of course, Mitchell has a fair amount of influence on Capitol Hill, which is where the most pressure came from forcing the union to accept changes in steroid testing policies in the first place.

All this suggests that whatever level of respect Mitchell has and deserves, he is not a neutral observer in these discussions, at least in the eyes of the union.

The sad thing is that it looked as if baseball owners and players were getting along better than ever before until the recent steroid problem reared its ugly head.

Owners and the union worked together to sponsor the successful World Baseball Classic. And they agreed to reopen the current labor agreement not once but twice, to toughen rules on steroid testing, albeit in the face of strong pressure from Congress.

With the league seeing record profitability and discovering new revenue sources from the Internet and international markets, it seemed likely that owners and the union could have been heading towards a relatively smooth round of negotiations on a new labor deal. Nothing makes it easier to split up a pie than a bigger pie.

That might still happen -- money normally trumps other issues in labor talks.

And while lots of fans have been holding up signs accusing Bonds of being a cheater as he approaches one of baseball's hallowed marks, ticket sales and television ratings still remain strong this season.

But if friction over the steroids issue means an end to the recent cooperation between Major Leagues Baseball and the MLB Players Association, the game's popularity won't be as bullet proof.

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For a look at the money flowing into baseball from the Internet, click here.

For SI.com's look at Bonds' joyless chase of Ruth's home run mark, click here.

For SI.com's look at what Barry Bonds' No. 715 home run ball might be worth, click here.