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New York Giants' rookie linebacker Mark Herzlich stepped off the plane in Indianapolis to play against the New England Patriots in Super Bowl XLVI and immediately took to Twitter to express his gratitude. He was thankful not just to be there, but to be alive.

"2 yrs ago I was told I might never walk again. Just WALKED off plane in Indy to play in The #SuperBowl. #TakeThatSh*tCancer," he tweeted.

In 2009, Herzlich was diagnosed with Ewing's sarcoma, a rare form of bone cancer. The cancer was isolated to his left leg and the initial prognosis was not positive for the promising Boston College football star.

"They felt the NFL was a long shot," Herzlich's father,  Sandy, told ESPN last summer. "They were first happy if they could save his life and they were happy if they could save his leg."

Herzlich was told there were three possible outcomes.

"The worst-case scenario is obviously [that] it gets into other parts of your body and it completely kills you," he told ESPN. "Second worst-case scenario is if they saw a small fracture in the bone and it was seeping out. Then they would have to amputate my leg right away within hours of finding it out. … Then better than that would be to remove that portion of the leg, putting in a cadaver bone and being in a cast for six months from the waist down, not ever being able to run again."

It turns out there was a fourth and even better option.

Herzlich responded phenomenally to aggressive chemotherapy and radiation. He was given the choice to forgo surgery and continue treatment, saving his football career, but increasing the likelihood that the cancer could return, or have surgery, ending his football aspirations, but likely eliminating the cancer.

Herzlich decided to keep his dream alive.

After missing the 2009 college football season to undergo treatment, he took the field for Boston College in 2010. He started in all 13 games, but did not catch the eye of NFL scouts and went undrafted.

Herzlich continued training and eventually signed as a free agent with the New York Giants.

Now, one year into his NFL career he's walked off the plane in Indianapolis and is getting ready to run onto the field at Lucas Oil Stadium, two things, that just three years ago seemed nearly impossible.

 ESPN contributed to this report.