HOUSTON — Texas Rangers President Nolan Ryan is in a Houston hospital undergoing tests on his heart.

The Rangers said in a statement Monday that 64-year-old Ryan is “resting comfortably and reports he is feeling better.” He is expected to be released from the hospital in a few days.

Ryan had a double-bypass operation in 2000. Doctors at that time also discovered another, undisclosed condition. The team’s news release said the discomfort began while at his home in Georgetown on Sunday morning and “is believed to be a recurrence of the heart condition which he has previously experienced.”

Ryan had been expected to join the Rangers in Anaheim, Calif., on Tuesday night for the start of a three-game series between his AL West-leading club and the Angels, who are in second place, four games back. He was scheduled to throw out the ceremonial first pitch and to take part in a ceremony inducting Gene Autry, the Angels’ late owner, into the team’s Hall of Fame.

Ryan is a member of the baseball Hall of Fame, holding the records for most no-hitters (seven) and strikeouts (5,714). He’s been running the Rangers since 2008 and became part-owner last summer. Texas went to the World Series for the first time last fall.