Washington (CNN) Senate Minority Leader Harry Reid said Friday he won't seek reelection in 2016, and endorsed New York Sen. Charles Schumer as his successor for his leadership post.

The fifth-term Nevada Democrat has spent months denying retirement rumors, which grew louder after he suffered serious injuries in an exercising accident on New Year's Day. He said in a video posted on Twitter and YouTube that the bruises were "nothing," but added that "this accident has caused us for the first time to have a little bit of downtime ... time to ponder and to think."

President Barack Obama praised Reid on Friday, calling into an NPR interview that the Nevada senator was giving to say that Reid was "one of my best partners and best friends."

"Harry is unique and he's got that curmudgeonly charm that is hard to replace," Obama told Nevada Public Radio. "I'm going to miss him. But the good thing is that I'm going to leave this place at the same time."

"Well I'll be damned," Reid responded when he heard Obama was calling into the interview.

Reid was a top GOP target and expecting a fierce reelection fight, and he says in the video that he feels it would be "inappropriate" for him to "soak up all those resources" while Democrats have a real shot at taking back the Senate. In an interview with The New York Times , Reid notes that many of Democrats' top targets are in big, expensive states, naming Pennsylvania, Missouri, Florida and Maryland as examples.

"The decision I made has absolutely nothing to do with my injury, and it has nothing to do with my being majority leader, and it certainly has nothing to do with my ability to be reelected, because the path to reelection is much easier than it probably has been any time that I've run for reelection," he said in his video announcing his retirement.

A member of Reid's staff tells CNN that the senator made the decision to retire with his family around Christmas, but told his staff that he wanted two months or so to sit on it before announcing it.

When his eye injury happened, on New Years' Day, it became clearer to him that he should retire. He hesitated, however, because he didn't want the decision to be seen as a result of his injury.

This aide says Reid has been telling people in private meetings that it's not so much about how he feels physically, which he says is great — the decision was based on how he would feel in eight years, which remains an open question. Reid, the source said, doesn't want to be one of the senators who's perceived to have stayed in the Senate past his prime.

Reid told The New York Times: "I want to be able to go out at the top of my game."

The notorious sports fan and boxer added: "I don't want to be a 42-year-old trying to become a designated hitter."

In interviews Friday afternoon, Reid named Schumer as the person he'd like to replace him in his leadership post.

"It's the caucus' decision, but he thinks (Sen.) Schumer has earned it," Reid's spokesman Adam Jentleson said, adding that Reid has also expressed his views to Illinois Sen. Dick Durbin, who was also considered a possible replacement.

JUST WATCHED Sen. Harry Reid on his Nevada upbringing Replay More Videos ... MUST WATCH Sen. Harry Reid on his Nevada upbringing 02:26

A top Democrat on the Hill tells CNN that Schumer intended to start making calls later Friday morning to some of his fellow Democratic senators, trying to begin the process of succeeding Reid.

Schumer issued a statement within minutes of the announcement praising Reid as "one of the best human beings I've ever met."

"His character and fundamental decency are at the core of why he's been such a successful and beloved leader. He's so respected by our caucus for his strength, his legislative acumen, his honesty and his determination. He has left a major mark on this body, this country, and on so many who have met him, gotten to know him, and love him," Schumer said.

Durbin announced Friday afternoon that he was endorsing Schumer as well.

Reid, who was first elected in the House in 1982 and to the Senate in 1986, rose to Senate Democratic leader in 2005 and served one of the longest tenures as floor leader in Senate history.