By revoking the Astros' top pick in the draft, Major League Baseball is "putting players and fans first" by addressing a violation by the organization, Commissioner Rob Manfred said on Friday.

Speaking at his annual winter league press conference in Arizona, Manfred was asked if he was upset the Houston Astros had not followed his direction and admitted that its scouting director and scouting coordinator had signed a document agreeing to "immediately notify MLB" of any violation.

"We are putting players and fans first, not only by enforcing the rules, but by sending clear signals about the expectations of everyone involved in the system," Manfred said. "That's a big deal for us, and it's an important way that we are addressing the issue of professional baseball. I'm disappointed that those issues were not addressed earlier, but I was determined to make sure they would be addressed early, and I'm glad that they've been."

Manfred sent the Astros a letter on Nov. 15 stating that he was preparing a list of a maximum of 19 players to be disqualified and revoked from being signed by third-party promotional agents.

The league said the Astros were aware that the document was being drafted but had signed it without knowing what it contained. The document, known as a "code of conduct," is intended to instruct third-party promotional agents to not engage in any illegal or unethical conduct.

Houston has appealed the penalty and will have the matter reviewed by an arbitrator.