Kelcher played college football with the SMU Mustangs and earned consensus All-American honors as a senior in 1974.

[1] Entering high school at Beaumont French,[2] he was only interested in playing baseball, but the coaches placed him in football.

As a senior in 1974, he was named National College Lineman of the Week by the Associated Press after recording 16 unassisted tackles and assisting on eight others in an 18–14 win over No.

Standing 6 feet 5 inches (1.96 m), he once said his weight varied between 280 pounds (130 kg) and infinity;[5] he wore size 17EEE shoes.

[8] His teammates voted him the Chargers' most valuable player in 1977, when he helped the team set a then-team record of 44 sacks.

[10] On November 18, 1979, against the Pittsburgh Steelers at San Diego Stadium, he asked Chargers coach Don Coryell to make Rolf Benirschke a captain for the day.

In a pre-game ceremony on the field, Kelcher assisted his weakened teammate, captured in an iconic photo of the lineman, about 350 pounds (160 kg) then, holding Benirschke's hand as they walked together.

[15] In the Epic in Miami, the 1981 divisional playoff which became one of the greatest football games ever, the Dolphins were leading 38–31 in the fourth quarter and threatening to score again at the Chargers' 20 when Kelcher stripped the ball from Miami's Andra Franklin and San Diego's Pete Shaw recovered the fumble.

[26][27] Kelcher received first-team honors on the All-Southwest Conference football team of the 1970s,[28] and he was inducted into the Southern Methodist University Hall of Fame in 2012.

[22] He became co-owner with Doug English, a former college rival with the Texas Longhorns, in the warehousing firm Pro Line Warehouse and Distribution.