He played college football for the Iowa State Cyclones and was selected by the Washington Redskins in the fourth round of the 2001 NFL draft.

[5] He attended Maquoketa Community High School, where he was a letterman in football, basketball, baseball, tennis, and track,[6] as well as a member of the National Honor Society.

He led his team to key wins versus Iowa, Missouri, Kansas, Oklahoma State, and Colorado where he had more than 100 rushing yards.

The Cyclones defeated the University of Pittsburgh in the bowl game, and Rosenfels (23–34; 308 yards; 2 touchdowns) was named Offensive MVP.

[13] Rosenfels, selected by the Washington Redskins in the fourth round of the 2001 NFL draft, spent one season as the team's third-string quarterback.

In 2006, the Houston Texans trailed the Tennessee Titans 21–3 before he threw three second-half touchdown passes to cut the lead to 28–22 as time ended the comeback.

The Sporting News' February 2007 off-season awards issue predicted that Rosenfels would be 2007's Tony Romo, the breakout quarterback of the year coming from a backup role.

Rosenfels fumbled twice, one of which was returned for a touchdown after he attempted to hurdle multiple defenders, after which the Colts took the lead and sealed the 31–27 victory following a last-minute interception.

[26] Rosenfels was originally supposed to battle Tarvaris Jackson for the starting spot, but his role changed to third-string quarterback after Brett Favre was signed.

[27][28] The Dolphins chose Rosenfels after also working out Kellen Clemens, J. P. Losman, Brett Ratliff, Jim Sorgi, and Charlie Frye.

He also serves as a color analyst for Iowa State games on Cyclones TV and a radio host for ESPN 1500 in Minnesota.

In 2018, he joined the cast of Late Night Tailgate[32] a touring sports discussion and comedy show produced by MBM Entertainment, The Kicker and IMG Artists.

As part of this tour, Rosenfels made both his standup comedy as well as his singing debut at Irving Arts Center on October 10, 2018.

His a capella performance of "I Will Always Love You," written by Dolly Parton and later recorded by Whitney Houston was captured on film by the Irving Community Television Network.