In his senior year, he averaged 33.1 points and 11.0 rebounds per game, and also shot 69% from the field and 82% from the free throw line.

The Heels scored a surprisingly easy 77–58 win over the Wildcats, but suffered another injury blow, this time involving Zeller.

With 1:26 left in the game, Zeller went for a breakaway dunk off a turnover, but was fouled by Kentucky's Ramon Harris before he could score.

[5] X-rays showed that Zeller had broken both of the major bones in his lower left arm (the radius and ulna).

Zeller made his return during his freshman season on February 18, 2009, in the Tar Heels' home game against North Carolina State, playing 8 minutes and scoring 2 points.

Both accolades made him eligible to have his jersey honored in the rafters of the Smith Center at the conclusion of his college career.

Zeller announced that he was entering the 2012 NBA draft along with North Carolina teammates Harrison Barnes, Kendall Marshall and John Henson.

[10] On October 11, 2013, Zeller underwent an emergency appendectomy procedure to remove his appendix and was subsequently ruled out indefinitely.

[11][12] He recovered from the surgery in time to face the Brooklyn Nets in the team's 2013–14 season opener on October 30.

[18] On December 16, he scored a season-high 12 points in a loss to the Detroit Pistons, hitting 5-of-7 from the field in less than ten minutes.

[21] On June 29, 2016, the Celtics tendered a qualifying offer to make Zeller a restricted free agent.

[25] On February 5, 2018, Zeller was traded to the Milwaukee Bucks in exchange for Rashad Vaughn and the rights to a future second-round draft pick.

[31] On June 24, 2020, the San Antonio Spurs signed Zeller to their roster to complete the 2019–20 season following the restart of league play coming out of the COVID-19 pandemic.