In 1995, the Sandman entered the major leagues for the first time of his career. After dominating the minor leagues as both a starter and reliever (Rivera can boast a 2.35 minor league ERA), Mariano was called up to the big leagues. 25 year old Rivera pitched in 19 games for the Yankees that season (10 starts), and gave up ugly numbers. He allowed 11 homers in only 67 innings, having the worst HR/9 ratio of any pitcher who started 10 games that season. His ERA was at 5.51, and his brilliance in the minors didn't seem to be translating to the big leagues. But, it was a small sample size, and the decent Yankees (at that time) let him return in 1996.
It was in '96 where Mo became a full time reliever. After a managerial change (Buck Showalter was manager in '95) to Joe Torre, the Yankees became World Series champions in '96. Rivera totaled 26 holds in '96, and was the main setup man to then closer John Wetteland. But the important part of 1996 was that Mariano Rivera recorded his first save of his career. Yes, his first. He finished the season with 5 saves, but little did he know that 5 saves would be only .07% of all of his saves to this date.
Over the 1998 and 1999 seasons Rivera had a 1.87 ERA and 81 saves in only 90 save opportunities. Yes, Rivera was already a lights-out closer, and had plenty of career left in him. He had already won three World Series, and already had a full career. But, heading into 2000, he was only 30.
From 2000 through 2011, Mariano won two more world series, and four pennants. He totaled 474 saves in that 12 year span, and only missed the all star game twice. His presence on winning teams definitely helped him get a ton of saves, but it also takes a lot of dominance and dedication had already helped him pitch into his early 40s, something very few pitchers can do. In 2011, Rivera was still throwing in the mid-90s, and able to get hitters out at 41 years old. He knew, however, his time was up very soon, possibly in 2012.
2012 came around, and disaster struck. Rivera fell to the ground at Kaufman Stadium before gameplay, and Yankees nation was devastated. Mo, usually very durable, had torn the ACL tendon in his knee. Likely the end of his season (it was), and possibly his career, fans hoped Sandman would be able to recover, because he deserved better, and deserved to end his career healthy. Mariano knew that, too, and worked extra hard, because it's very hard to recover from an ACL tear, let alone a 42 year old man.
Mo is a living legend. Simply put, he'll be the player that your kids will want you to tell them stories about. He's the player that will never be forgotten, not only for his baseball, but for his dedication to everything his does. Someone, in time, may break his records (not very likely), but it will be nearly impossible to find the next Mariano Rivera. Take in every second you watch him, take in how he pitches, and take in every out he records, even if it may only be three.
In five years, Mo will find himself in Cooperstown, along side Mays, Clemente, Ruth, Musial, Cy Young, and others. He, however, can separate himself from the others, as he is the greatest closing pitcher to step on to the field. He is a phenomenal player that will never be forgotten. Everyone who witnessed the Sandman in their lifetime can already consider themselves lucky, as he will be one and only Mariano Rivera.