He played college football at Missouri before leaving early for the 2011 NFL draft after his junior year.

He has also played for the San Francisco 49ers, Arizona Cardinals, Tennessee Titans, Tampa Bay Buccaneers, and Kansas City Chiefs.

Rated as a five-star recruit by Rivals.com, Gabbert was listed as the highest ranked pro-style quarterback in the nation.

[5] He initially gave a verbal commitment to the University of Nebraska Cornhuskers, but rethought his decision after head coach Bill Callahan was fired.

[7] He saw action in five games in reserve duty, leading the Tiger offense to a touchdown against Colorado and a field goal against Nevada.

[2] Gabbert had a strong debut in 2009, throwing for 313 yards with three touchdowns in the air and another one on the ground against the Illinois Fighting Illini in the annual Arch Rivalry.

[23] Though not slated to serve as starting quarterback, Gabbert quickly earned playing time under head coach Jack Del Rio after David Garrard was released in the preseason and Luke McCown performed poorly in the first two games.

[24] Gabbert played in his first NFL regular season game on September 18, 2011, against the New York Jets in Week 2.

[31] Pete Prisco of CBSSports.com predicted that Gabbert's potential remained high, and that many of his struggles could be attributed to injuries and the unfavorable circumstances around him, including a rush-centered offense, a lack of talented quarterbacks ahead of him, and a weak receiving corps.

[33] In Week 3, a 22–17 victory over the Indianapolis Colts, Gabbert threw a career-high 80-yard touchdown pass to Cecil Shorts.

[34] Gabbert struggled in the following weeks, including a loss to the Chicago Bears, in which he threw two interceptions and fumbled once.

[35] Against the Oakland Raiders, Gabbert tore the labrum in his non-throwing shoulder during the second quarter, and he was replaced by Chad Henne.

The team cited in an official press release that Gabbert had also been playing with a torn labrum in his left shoulder that would require surgery.

[40] Gabbert returned for the 2013 season under new head coach Gus Bradley, but played only three games, finishing with just one touchdown and seven interceptions.

[42] During the season opener, he suffered a lacerated right hand, which required 15 stitches and prevented him from playing the following week against the Raiders.

[45] Gabbert made his 49ers regular-season debut on October 19, 2014, during the team's 42–17 loss to the Denver Broncos in Week 7.

[50] The following day, the 49ers announced that Gabbert would remain the starter when the team played the Seattle Seahawks on November 22.

[52] Gabbert finished the 2015 season with 2,031 passing yards with ten touchdowns and seven interceptions for an 86.2 passer rating.

[58] He started the season as the third-string quarterback behind Carson Palmer and Drew Stanton under head coach Bruce Arians.

[59] During the game, Gabbert threw for 257 yards and a career-high three touchdowns as the Cardinals lost to the Houston Texans by a score of 31–21.

[60] Gabbert was benched on December 18, 2017, as the Cardinals' starting quarterback in favor of Stanton after not throwing for a touchdown in back-to-back games.

During that game, he struggled and was limited to eight passing yards before leaving the 9–6 road victory with a concussion.

[66] Due to another injury to Mariota, Gabbert started the final game of the 2018 season with a Wild Card playoff spot on the line.

[77] He started the regular season finale against the Los Angeles Chargers after the Chiefs elected to rest Patrick Mahomes.

[83] On December 29, 2022, while riding jet skis, the Gabbert brothers helped save four individuals in the water near Davis Islands and Peter O. Knight Airport after an emergency landing of a helicopter.

Blaine says he saw what "looked like a crew boat in the water that had broken up in about four pieces and I vaguely remember seeing like two yellow life jackets."