3 years shortest career spans http://www.livestrong.com/article/15...er-nfl-player/ http://www.livestrong.com/article/15...er-nfl-player/ Longest and Shortest NFL careers by position shortest careers http://www.livestrong.com/article/15...er-nfl-player/ source Studie Longest and Shortest NFL careers by position http://www.livestrong.com/article/15...er-nfl-player/ with the shortest average career length 2.57 years average career just 2.57 years Livestrong.com http://www.livestrong.com/article/15…er-nfl-player/ average career is 3.3 years NFL Player’s Association http://www.livestrong.com/article/15...er-nfl-player/ 2.57 years http://www.livestrong.com/article/15...er-nfl-player/ http://www.livestrong.com/article/15...er-nfl-player/ NFL player's career is about three years Longest and Shortest NFL careers by position average career is 3.3 years