More than 20 years since retiring from the NFL, Joe Montana says the wear and tear of the sport continues to take a toll on his now-59-year-old body.

In an interview with USA Today Sports, the four-time Super Bowl-winning quarterback detailed the ailments he continues to deal with after leaving football following the 1994 season.

They include:

-- Arthritis. Montana told USA Today Sports of the inflammation in his hands: "In the middle of the night they hurt like crazy." He also has arthritis in one elbow and both his knees.

-- A balky knee. Montana can't straighten his knee despite, according to USA Today Sports, having a half-dozen surgeries on it. He said he can't run much anymore and has been told he'll "need a knee replacement when I can't walk."

-- A bad neck. Montana said he has already had three neck fusions and a fourth very well could be on the way. "The path of a nerve they think is being affected," he told USA Today Sports.

-- A troublesome eye: Nerve damage has left Montana with what he labeled a "lazy eye to some degree because every time you're tired, it kind of goes wherever it feels like a little bit." He added to USA Today Sports: "Not dramatic but just enough where you can't read or you have to refocus."

Joe Montana told USA Today that he's had six knee surgeries and three neck fusions. Getty Images

The constant physical woes are an everyday reminder of his 15-year playing career, 13 of which were with the San Francisco 49ers. He's back in the city this week as Levi's Stadium prepares to host Super Bowl 50 in nearby Santa Clara.

Montana will handle the coin toss before the Denver Broncos and Carolina Panthers vie for an NFL championship Sunday night.

"The mental part was hard initially when I first retired. Because it's quick -- cold turkey, the game's gone," Montana told USA Today Sports, recalling the years since he retired. "Then the physical stuff tries to catch up with you."

And when it does, it keeps Montana from doing some of the things he loves, including physical outings with his wife and three kids.

"My whole family likes to live on the edge, so some of the things I regret that I can't do with them," Montana told USA Today Sports. "Like snowboarding. I fell like 50 times within 30 yards off the top of the ski lift. ... I love basketball. I can't play basketball. I can shoot, but that's about it. I can't run up and down the court. My knee just gives out.

"I tried a little bit of skiing, but unfortunately when you get weight on one ski under my left knee, it's just not very strong. After my first back surgery, what kind of compounds things, is my sciatic nerve has been damaged. So the muscles along my sciatic nerve into my left foot have been numb since '86."

It's a price many players must pay to play the game, Montana believes.

"Unfortunately," he said, "most of us leave this game with things that linger."