Bryant hired Parker when he came out of Oklahoma State for the 2010 NFL draft, and he negotiated a five-year $11.8 million deal.
But toward the end of the 2011 season, Bryant let Parker go and hired Rosenhaus. At the time, Bryant said it was a difficult decision because he valued Parker's knowledge of the NFL. Bryant also hired Parker based on recommendations from Hall of Fame cornerback Deion Sanders.
"He's making decisions he thinks will better him," Cowboys chief operating officer Stephen Jones said. "We support him in the decisions he makes. If he feels that is going to make him better, we support him. I have no issues with Drew or Eugene."
Added Cowboys owner/general manager Jerry Jones: "Nothing against Rosenhaus, but I know what the quality person Eugene Parker is and I think Dez benefits from that."
Rosenhaus wouldn't comment, and Parker couldn't be reached.
Bryant was not available for comment.
Bryant enters his third NFL season with a major legal issue hanging over him.
The Dallas County district attorney's office is reviewing a Class A misdemeanor charge against Bryant for assaulting his mother, Angela. Bryant and his mother said no violence occurred during a July 14 incident.
Jerry Jones said Bryant will be under strict guidelines as a result of the alleged incident.
"I'm as firm as I can be," Jones told ESPNDallas this week. "I don't know when I've ever been firmer. He's in a situation where he has some responsibilities and consequences that will result in change."
Information from ESPNDallas.com's Todd Archer was used in this report.