A big key: Will Bud Selig get involved in discipline of Alex Rodriguez?

Will commissioner Bud Selig invoke the "best interests of baseball'' clause in punishing Alex Rodriguez? The answer could come Monday.

Selig's direct involvement might not only prevent Rodriguez, 38, from rejoining the Yankees immediately but perhaps end the third baseman's career, pending an appeal.

If a penalty is imposed under the guidelines of the Joint Drug Agreement and Rodriguez appeals it, he will be eligible to play until an arbitrator makes a ruling. If Selig invokes the "best interests of baseball'' clause in administering the penalty, Rodriguez will be sidelined until a decision on the appeal is rendered.

Rodriguez has missed the entire season while rehabbing after left hip surgery and a subsequent left quadriceps strain. He played in his final rehab game for Double-A Trenton Saturday night and hopes to rejoin the Yankees Monday in Chicago.

MLB is close to announcing punishment for Rodriguez and others linked to performance-enhancing drugs associated with Biogenesis, the former anti-aging clinic in Miami.

While most of the accused players are expected to receive 50-game suspensions under provisions of the Joint Drug Agreement, Rodriguez's penalty is expected to be more severe because of alleged actions beyond the scope of the JDA. Anywhere from a lengthy suspension to a lifetime ban has been reported. ESPNNY reported Saturday that he is likely to be suspended through the 2014 season, which would amount to 214 games.

The Associated Press has reported that the Yankees expect Rodriguez to be accused of recruiting other athletes for Biogenesis, of attempting to obstruct baseball's investigation and of not being truthful with MLB in the past when he discussed his relationship with Dr. Anthony Galea, who pleaded guilty two years ago to a federal charge of bringing unapproved drugs into the United States from Canada.

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Indications are Selig has been trying to hold off from invoking either Article XII(B) -- the "best interests of baseball'' clause -- or, less likely because of Player Association action, Article XI(A)(1)(b) of the Basic Agreement, which points to the "integrity of the game'' and would allow Selig to act as arbitrator.

MLB attorneys reportedly have discussed a negotiated settlement with Rodriguez, but it appears the talks were fruitless. A source familiar with his plans said Saturday, ''They're [MLB] done talking, we're done talking. We haven't been talking.'' A source repeatedly has said Rodriguez intends to appeal any discipline by MLB.

Selig could resort to any penalty he deems fit. But Washington attorney Stanley Brand, who in 2005 represented MLB in connection with the congressional investigation into the sport's steroid policies, said the commissioner's power, omnipresent as it may be, is a double-edged sword.

"The commissioner is at the apogee of his powers when he acts on integrity-of-the-game issues, as I think this is,'' Brand said. But he added that there is always the concern of a legal challenge.

"It's a balance,'' he said. "You always have a concern -- with no disrespect to the federal judiciary -- that some errant judge will misconstrue the agreement we've all operated under in baseball for 100 years. So you are reluctant to thrust yourself into that forum.

" . . . I learned a great thing from Tip O'Neill when I worked for him. The perception of power is power. And when you lose that perception, you lose something. You lose the aura of invincibility. The commissioner has a tough enough job without having it eroded by decisions.''

Should Selig act, Rodriguez's attorneys could seek a temporary restraining order in federal court. "A TRO I think is a reach,'' Brand said. "Federal courts have been very reluctant to step into anything that deemed arbitrable subjects the agreements that baseball and the players have signed.''

That would return the matter to the jurisdiction of baseball and its arbitration system. And that outcome is not predictable for either side. The arbitrator, Fredric Horowitz, could uphold MLB's decision, overturn it or modify the discipline.

Roger I. Abrams, professor of law at Northeastern University, has presided over salary arbitration in MLB and is well- versed in the grievance procedure. He said MLB's penalty would have to be justified.

"[The player] committed an act or acts which seriously interfere with his abilities to serve as a ballplayer in the future. That's what they would have to prove to me, and you'd really have to convince me what happened. You have to go on what's clear and convincing.''