I’ve never been a fan of the Dallas Cowboys, but Jon Kitna remains one of the good guys of the NFL. After retirement, he went to work as a math teacher and football coach at his high school alma mater, getting students with learning disabilities to understand algebra (and thus be prepared for higher-level math classes in later years).
After the unfortunate injury to starting quarterback Tony Romo, the Dallas Cowboys called upon Kitna for emergency service. He plans to donate his one-game salary back to the high school.
Reference: http://bleacherreport.com/articles/1901693-jon-kitnas-salary-decision-proves-his-return-is-noble