Many thought they had seen the last of Mariano Rivera when he tore the anterior cruciate ligament and meniscus in his right knee in Kansas City, Mo., on Thursday before the game between the New York Yankees and the Kansas City Royals.

The injury will likely end his season, and, because Major League Baseball's all-time saves leader is 42 years old, many have wondered whether it would end his career, as well.

But Rivera said on Friday he will be back on the pitcher's mound in the future.

I'm coming back. Write it down in big letters: I'm not going down like this, Rivera told reporters in Kansas City, according to I love to play the game. I don't think, to me, going out like this is the right way.

Rivera also indicated via his official Twitter account that he does not plan to let this injury conclude his career. Thank you fans, friends & family for your prayers, well wishes and support. he tweeted. I will be ok. I will be back.

In spring training, Rivera hinted this might be his final year in the big leagues. It's unknown when he will return from the injury, but one thing seems to be for sure -- Rivera will pitch again.