I know its hard to believe, but i found a article related to Montanas Injury(87), the title of the article is "A Little Miracle By The Bay", and describe how Montana was depresed and diagnosed with a "season done" and maybe his career.. There are few quotes that i really love, so i am going to copy some.. but you can check all the article.. its really good.
Depression
But Montana was depressed during the days following the operation. "I considered retirement," he said, "but I was in sort of an altered state. I was cross-eyed, and some of the things I thought I saw were bizarre. I thought water was running up the walls."
Doubt
Teammates Ronnie Lott and Clark visited Montana a few days after the operation. "Joe had to use a walker to see us to the elevator, and it exhausted him," says Lott. "As soon as the doors closed, Dwight and I looked at each other and both of us were thinking,' It's no way. Ever.' It was scary, and really sad."
Hard work and love for the game
After awhile Montana's thinking brightened, and he threw himself into a three-hour-a-day rehabilitation program of weightlifting, partial sit-ups, running and swimming. "I have my schedule, and the doctors have theirs," he said. "Naturally, I will push harder than they want." By early October, he was throwing footballs through a soccer goal in a Foster City park, with his wife, Jennifer, and a cousin working as shaggers. He was way ahead of schedule.
And you know what, before the surgery he was one of the greatest, and after.. won 2 superbowl and gain his reputation like the GOAT(Obviously.. before Manning Era).. http://sportsillustrated.cnn.com/vault/article/magazine/MAG1065470/index.htm And you can hear an interview with Montana.. http://www.yahoosportsradio.com/shows/joe-montana-peyton-can-come-back-7379/