Welschof was born on March 12, 1997, in Germany. He grew up in
Miesbach,
Bavaria, where he won youth championships in
skiing. He attended the
vocational high school (
Fachoberschule,
FOS) in
Altötting and graduated from there. After his graduation from high school, Welschof visited the United States in 2013, staying with a friend of his grandfather in
Jacksonville, Florida. He was told of
American football and received a suggestion that he might be good at the sport, something Welschof initially did not believe, due to being 16 years old at the time and never having played the sport. He learned of a service run by former
Canadian Football League (CFL) player
Brandon Collier called Premier Players International, designed to get European players opportunities in college football. Welschof contacted Collier and informed him of his measurements and ability to run a
40-yard dash in 4.5 seconds, then later proved his abilities to a doubtful Collier on a field covered in snow in below-freezing temperatures. Afterwards, he began receiving significant attention and received offers from a number of different programs, being ranked as the 12th-best defensive end recruit and a four-star prospect by
247Sports. He initially committed to play for the
Georgia Tech Yellow Jackets, but later flipped to the
Michigan Wolverines. ==College career==