Ex-Pittsburgh Steelers running back and former NFL analyst Merril Hoge says Roundup weed killer caused him to get cancer back in 2003 ... and now, he's suing.
The 54-year-old says he first mixed and sprayed the popular weed killer all over while he was working on a farm in Idaho back in 1977.
Twenty-six years later -- in Feburary 2003 -- he was diagnosed with Non-Hodgkin's Lymphoma ... and now, he's claiming it's the weed killer's fault.
In a new lawsuit obtained by TMZ Sports, Hoge says the makers of Roundup -- Monsanto Company -- knew an ingredient called glyphosate could potentially cause cancer ... but says they failed to properly warn him of the risks.
Hoge says if he had known the chemical's side effects ... he would have used a different, less dangerous product.
Now, Hoge is suing the company for an undisclosed amount ... claiming it caused him "life-threatening" cancer as well as a "diminished enjoyment of life."
For its part, Monsanto has categorically denied its product causes cancer.
Hoge played 8 seasons in the NFL -- 7 with the Steelers -- from 1987 to 1994 ... before head injuries forced him to retire after the '94 season.
He totaled 3,139 rushing yards and 21 rushing TDs in his career ... and became well known after his football days for becoming one of ESPN's top analysts.