Task: Question Answering
Input (English): Stefen "Stef" Djordjevic is a Serbian American high school defensive back who is gifted in both sports and academics. He is seeking a college football scholarship to escape the economically depressed small western Pennsylvania town of Ampipe and a dead-end job and life working at the mill like his father and brother Greg. He dreams of becoming an engineer right after he graduates from college. Ampipe is a company town whose economy is dominated by the town's main employer, American Pipe & Steel, a steel mill struggling through the downturn of the early 1980s recession. Stef gets through his days with the love of his girlfriend, Lisa Lietzke, and his strong bond with his teammates. Most of the film takes place after the big football game against undefeated Walnut Heights High School. Ampipe appears headed to win the game, when a fumbled handoff in the closing seconds—as well as Stefen's pass interference penalty earlier in the game—leads to a Walnut Heights victory. Following the game, Coach Burt Nickerson lambastes the fumbler in the locker room, telling him he "quit" the game. When Stefen retorts that the coach himself quit, the coach kicks him off the team. In the aftermath, disgruntled Ampipe fans vandalize Coach Nickerson's house and yard. Stefen is present and is a reluctant participant, but is nonetheless seen by Nickerson as the vandals flee. From there, Stefen deals with personal battles, including dealing with the coach blackballing him among colleges because of his attitude and participation in the desecration of Nickerson's yard and house. Stefen gets in an argument with Lisa, and his best friend Brian declines a scholarship offer to USC and plans to marry his pregnant girlfriend. 
Question: What's the nickname of the person who gets removed from the team after standing up to the coach?
Output (English): Stef