Colin Montgomerie checked into hospital due to chest pains early on Sunday but was cleared in time to play his final round at the Senior Players Championship in Massachusetts.
The Scot, one of the best players never to have landed a regular major title, has won three major championships in the over-50s ranks since joining the tour in 2013.
Montgomerie said he felt discomfort at the end of his third round but returned to the course on Sunday after treatment to shoot a 68 and finish third, nine strokes behind winner Bernhard Langer.
"I decided the prudent thing was to go in and get checked," Montgomerie told reporters of his visit to Massachusetts General Hospital. "I had all these CAT scans and all this stuff.
"I had two hours to do it this morning and the staff of the hospital was superb."
Montgomerie, who won 31 times on the European Tour and tasted Ryder Cup success as a player and captain, will head to Chambers Bay for the US Open looking to finally go one better than his five runner-up finishes at majors on the regular tour.