Yell attended San Jose State University and played for the Spartans football team as a defensive back, in 2009 under coach Dick Tomey and from 2010 to 2012 under Mike MacIntyre. As a freshman, Yell played 10 games and started at cornerback in the last six games of 2009 and had 19 tackles and a pass deflected. Yell also became the punt return specialist late in 2009. San Jose State finished the 2009 season 2–10. In 2010, his sophomore year, Yell played all 13 games and started 10. He had 44 tackles, 11 passes deflected, and one interception. He returned one punt for six yards and 32 kickoffs for 645 yards. In Mike MacIntyre's first year as head coach, San Jose State went 1–12 this season. For his junior year in 2011, Yell played the final 10 games of the year and started 6. Yell had 37 tackles, an interception, 5 tackles, a pass deflected, and 3 punt returns for 42 yards. In San Jose State's 38–31 win over Colorado State on October 1, Yell intercepted a Colorado State pass in Colorado State's final possession to seal San Jose State's first road win in 13 games. San Jose State improved to 5–7 in 2011. As a senior in 2012, Yell played all 13 games and had 41 tackles, 9 passes deflected, and 15 punt returns for 42 yards. San Jose State finished the season 11–2, including a victory over Bowling Green in the 2012 Military Bowl in Washington, D. C. Yell broke up 3 passes in that game. Yell graduated from San Jose State in 2013 with a B.A. in sociology.
On October 7, 2013, during the team's practice roster expansion period, the CFL team BC Lions signed Yell, who would remain on the practice roster through the end of the season. In his preseason debut with the Lions on June 14 against the Edmonton Eskimos, Yell forced a fumble recovered by teammate Alex Hoffman-Ellis, and this play set up BC's winning field goal in a 14–11 win. Yell also had two tackles and an interception. On August 1, Yell made his first regular season CFL interception in BC's 25–24 win over the previously undefeated Calgary Stampeders and returned it 34 yards for BC's first score of the game. With 51 seconds left and BC leading, Yell forced a Calgary fumble, and BC ran out the clock to 4 seconds remaining. BC won after Calgary's final play was an incomplete pass.
Toronto Argonauts
Yell became a free agent in 2018 and subsequently signed with the Toronto Argonauts on February 17, 2018, then Yell was released in 2019.