Greenberg is one of three who sources have confirmed are bidding for the Rangers. Former agent Dennis Gilbert, who is now a special assistant with the White Sox, is also one of them and Jim Crane, a Houston businessman who owns a freight-forwarding company, is another.
Crane was also one of the bidders for the Chicago Cubs last year and was once a pitcher at the University of Central Missouri.
Ryan said he doesn't know Crane, even though they both have extensive connections in the Houston area. Those are the three bidders that have been identified but that doesn't mean they are the only ones.
"There may be others that I'm not aware of," Ryan said.
Rangers owner Tom Hicks has had all or part of the team up for sale since Spring Training. Hicks initially was hoping to sell 49 percent and retain controlling interest. He has since expressed willingness to sell either the whole franchise or controlling interest in order to pay off substantial debt in the Hicks Sports Group.
Hicks could still stay involved in some manner, depending on the final terms of the sale. Any sale isn't expected to be finalized until early next year.
"I don't know what the driving force will be for Tom," Ryan said. "I don't know when this will get to moving and when we will have a feel for the time schedule."
Greenberg owns Minor League teams in Myrtle Creek, S.C., and State College, Pa. He sold a team in Altoona, Pa., last year. Ryan also owns two Texas Minor League teams in Round Rock and Corpus Christi in addition to his other business interests.
In January 2008, Hicks hired Ryan to be the Rangers' club president. Ryan said he doesn't think the potential sale of the club has affected the players on the field, but it has been on others' minds as the season has progressed.
"Obviously I think from the front-office people there is some uncertainty [about] what will happen if there is a change in ownership," Ryan said. "People wondering who it will be, what direction it will go and how it will impact the front office of the Rangers."
Any change in ownership would require the approval of the other 29 teams.