The Rangers, in first place in the American League West, are actively pursuing starting pitching. They've inquired about Mariners left-hander Cliff Lee, among many other pitchers. Right-hander Rich Harden and left-hander Derek Holland are on the disabled list, and long reliever Dustin Nippert is filling in as the fifth starter.
The Astros acknowledged last month that Oswalt's agent, Bob Garber, called owner Drayton McLane and requested the three-time All-Star be traded. Oswalt has a no-trade clause and would have to approve any trade the Astros make.
Oswalt was asked Friday about his interest in the Rangers.
"I'm open," he said. "Just have to wait and see what works for both of us."
Ryan said the interest in Oswalt is only preliminary.
"There hasn't been really any conversations I've been aware of here in the last week to 10 days," Ryan said. "I think, from the Astros' perspective, that would pick up as we would get closer to the [non-waiver] Trade Deadline in July."
Astros general manager Ed Wade has a policy of not commenting on trades.
Oswalt is 5-8 with a 3.12 ERA in 14 starts this year for the Astros, who entered Friday at 26-41 and near the bottom in the National League Central. He has 12 quality starts and has thrown at least seven innings and allowed no more than two runs in each of his five road starts this year.
"I think he's phenomenal," Ryan said. "I think he's been one of the top four or five pitchers in the league for quite a while. He's a big-game pitcher and consistent with his stuff, as we see this year, with the way he's approached each game he's been in. He's special."
Oswalt is making $15 million this year and is scheduled to make $16 million next year. The Astros have a $2 million buyout for 2012 or he will be paid $16 million.
The Rangers cannot take on significant payroll in any trade. But they can get other teams to pick up a high-priced player's salary if they add extra prospects to the package. The question is if the ownership situation will be resolved by the Trade Deadline. If the Ryan-Greenberg group takes over before then, the Rangers will have financial flexibility to add payroll in any trade without giving up additional prospects.
"Last October, we sat down and devised a budget for this year, and as long as we stay within that budget, we're fine," Ryan said. "If we go outside that budget, we have to get approvals. The only way I foresee that happens is you acquire somebody that has salary that would put you over what your limits are. Will that happen? I don't know. We've budgeted for the Trade Deadline, and we feel we might be in position to improve our ballclub, but we don't really know."
Ryan said he's hopeful the club's ownership situation will be settled in July.
"I think it's progressing and I think that from our perspective, it's going well," Ryan said. "We'd like to think, in July, we will get the opportunity to close the deal and the new ownership group will be the group we put together."