The casual baseball fan has probably heard the name of Dr. Lewis Yocum. But, they probably don't know who he is or what he does.
Everyone, though, has heard of Tommy John surgery.
And while Yocum may not have been the first to perform the procedure that essentially changed the game of baseball, he was certainly the one who perfected it.
In fact you can make the argument that few have contributed to the sport more than Yocum. There's never been a surgeon enshrined in any sports Hall of Fame and baseball doesn't have a contributor's wing in Cooperstown, but has anyone done more for the sport in the last 30 years than Yocum?
The 66-year-old Yocum died over the weekend after a battle with liver cancer which had been kept under wraps, so the news announced on Tuesday stunned the baseball community.
Yocum's practice was based at the Kerlan-Jobe Orthopedic Clinic, but he was also in his 36th season as the team physician for the Los Angeles Angels of Anaheim.
"The Angels family and MLB have lost one of baseball's finest gentlemen and truly outstanding professionals with the passing of Dr. Yocum," the Angels said in a statement. "Dr. Yocum's impact in the medical field will long be remembered across the country. The list of careers he extended is endless."
Yocum's specialty was the ulnar collateral ligament replacement procedure, known as Tommy John surgery after Dr. Frank Jobe, who created the operation back in 1974 to help the then-Dodgers pitcher resume his career.
"He could probably do the Tommy John operation better than I could," Jobe said on Tuesday.
Jobe, by the way, also should be in the Hall of Fame.
"Dr. Lewis Yocum was a giant in the field of sports medicine," MLB commissioner Bud Selig said in a statement on Tuesday. "He was an invaluable resource to not only the Angels franchise but players throughout all of Major League Baseball, team physicians and the members of the Professional Baseball Athletics Trainers Society.
"All of our clubs relied upon Dr. Yocum's trusted opinion and judgment. Throughout the last 36 years, the lives and careers of countless players benefited from his pioneering expertise, and he made our game on the field better as a result."
Yocum, of course, will best be remembered for his work on the elbow, but the legendary orthopedist also repaired and consulted on countless shoulders and knees. It was only a few weeks ago that Philadelphia Phillies right-hander Roy Halladay went to Yocum to get a better look at his ailing shoulder.
His client list reads as a who's who in Major League Baseball. Good luck finding a locker room that doesn't have someone who has been treated in some capacity by Yocum.
"He saved a lot of guys' careers," said Washington righty Jordan Zimmerman, who had the UCL surgery back in 2009. "He's fixed a lot of guys. He did a lot for the game of baseball. A tough blow for all the younger pitchers who have to go through it. He was a great guy. He saved my career. I wouldn't be here without him.
Quite simply, he was the doctor to the stars.
Among the numerous players and executives offering their Yocum condolences and stories on Tuesday, super agent Scott Boras chimed in on Twitter for just the second time since his corporation launched an account in December 2010.
"Dr. Yocum was a caring genius who had a profound impact on the game and its players," Boras wrote. "His plaque in the hall awaits."
Yocum changed the game with his work. He'll continue to be a pioneer in death when he one day becomes the first surgeon inside the hallowed walls of Cooperstown.