If not for a career’s worth of etching his name in baseball lore, Mariano Rivera probably wouldn’t stand out.

At 6-foot-2, 195 pounds, Rivera’s physique is hardly imposing. When he came up as a starting pitcher for the New York Yankees in 1995, his numbers were less than stellar: A 5.51 earned-run average who gave up 9.5 hits per nine innings.

Then they moved him to the bullpen. Then history was made.

At age 43, Rivera recently announced that this coming season will be his last. The man who went from a failed starting pitcher to the greatest closer to even play the game said it was time for him to call it a career.

From humble upbringings in Panama City, the Yankees initially signed Rivera as an amateur free agent in February 1990 to a contract with a meager $3,000 signing bonus. After his meteoric rise as a great relief pitcher, Rivera went on to earn more than $146 million over the duration of his career.

But his rise to stardom didn’t change who he was as a person. Athletes like Tim Tebow are often admired for their outspoken faith in God, and Rivera comes from a similar mode. When asked about adding his signature cut fastball to his repertoire in 1997, Rivera said the pitch was “given to me by the Lord.”

It’s this demeanor that makes Rivera a professional athlete who is also a genuine role model. It’s not just the career 2.21 ERA, the 608 saves (most of all time) or the amazing 0.70 postseason ERA. It’s the way he carries himself both on and off the field that truly sets him apart.

Rivera is known for entering the ninth inning with Metallica’s “Enter Sandman” blasting over the PA system in Yankee Stadium. Ironically, Rivera once said in an interview that the song was originally selected for him, that he didn’t know the lyrics and that he only listened to Christian music.

If you were to listen to his retirement announcement, Rivera would come off as oblivious to his own greatness as he is the lyrics of the song he enters to. “I don’t think I’m the greatest of all time,” he said. Rivera went on to say he instead wanted to be remembered as someone who edified his teammates, someone who put others first.

As Rivera begins his farewell tour around baseball this summer, baseball fans will get one last glimpse at a rare form of greatness — greatness not simply defined by accomplishments, but also by character.

But far be it for me to diminish Rivera’s on-the-field accomplishments. Any baseball fan can only sit and admire the cut fastball God blessed Rivera by giving him. To quote Braves great Chipper Jones, “It eats you up, like a buzzsaw.” Even in his later seasons, with diminished velocity, hitters have yet to figure out how to hit him.

When Major League Baseball retired Jackie Robinson’s No. 42 in 1997, all players who were wearing the number at the time were told they could continue wearing it. Rivera is currently the only active major leaguer still wearing No. 42, and he will retire as the last player to ever wear it.

While no one could ever truly live up to Robinson’s legacy, having a player like Rivera close the book on No. 42 is fitting. Baseball is losing not just a legacy, not just an icon, but one of the game’s best ambassadors. Not seeing a No. 42 will leave the game with a certain emptiness that will prove difficult to fill, no matter how skilled the next great closer is.