Rangers CEO and president Nolan Ryan underwent a series of precautionary tests in a Houston hospital on Monday that revealed no new developments with the recurrence of his heart condition, the club announced Monday afternoon.

Ryan, 64, continues to improve and is expected to be released in a day or two.

The Hall of Famer felt some discomfort early Sunday morning at his home in Georgetown, Texas, and checked into the hospital. Ryan, who had a double-bypass operation in 2000 and has a family history of heart disease, will continue to be treated with medication.

Ryan, who owns the record for most no-hitters (seven) and most strikeouts (5,714), added CEO to his title of president after former managing general partner Chuck Greenberg's departure in March. He was hired as club president on Feb. 6, 2008 by previous owner Tom Hicks and has helped oversee the business and baseball operations of the organization. He became an owner of the team last August, when the club was purchased by Rangers Baseball Express in an auction in bankruptcy court.

Ryan was scheduled to join the team in Anaheim for a three-game series starting Tuesday. The former Angel was supposed to throw out the first pitch Tuesday night as part of the Angels' Hall of Fame inductions, which this year include the late Gene Autry, the original owner of the team. Ryan was inducted into the club's Hall of Fame in 1992 and was to accept his Hall of Fame ring as well.

On Tuesday, the Angels announced that the ceremony will go forward as scheduled but that the team would like to have Ryan throw out a ceremonial pitch at a later date.

"We're going to talk to Nolan and see how he feels," Tim Mead, the Angels' vice president of communications, told the Los Angeles Times. "It meant a lot to him to take part in the program, and that invitation will be extended to him when he's ready and if he's available."

Richard Durrett covers the Rangers for ESPNDallas.com. Information from The Associated Press was used in this report.