"The stuff just exploded on me. That's how quickly it happened; you never knew what was going to hurt next," he said.
After being diagnosed and treated, Murphy recovered to the point where he could restart his career in the Senior PGA Tour, where he claimed eleven wins.
Given his early diagnosis and quick response to treatment, rheumatologists say there's a good chance Mickelson will be able to manage his disease while staying in the pros.
Because the immune-suppressant medication Mickelson is on will put him at increased risk for infection, he needs to be vigilant about monitoring his health and staying well rested, Kalunian says.
"Golf isn't high impact like football, but you still need to have high functioning small joints, especially those in your hands," says Ritchlin. "It's hard to say exactly how it will affect his game. You have to see how people respond in the first year or two [after diagnosis]."