He was signed as an undrafted free agent by the San Francisco 49ers in 2004, spending a majority of his short NFL career on the practice squad.

In 2019, two years following his hiring by Minnesota, Fleck led the Golden Gophers to one of their best seasons in half a century, earning their most wins since 1904.

Upon graduation, Fleck attended Northern Illinois University where he played wide receiver with the guidance of head coach Joe Novak.

As a senior, he led the Huskies with 77 catches for 1,028 yards and six touchdowns, a reception total that still ranks second on the school's single-season list.

49ers head coach Dennis Erickson labeled Fleck a "frickin' warrior" during the first days of rookie training camp.

Following Novak's retirement in 2008, Fleck was one of two NIU assistants to be retained by incoming head coach Jerry Kill, and also added the title of recruiting coordinator.

[18] One of Fleck's first actions as head coach was to rescind scholarship offers to incoming players who had verbally committed to Western Michigan.

The withdrawals occurred just weeks before the national signing day, and left players unable to arrange other Division I scholarships as slots were already filled at other schools.

"[19] Fleck made sports headlines after his hire with his charisma and attempts to energize to the WMU program, including dancing (The Harlem Shake), posting YouTube videos, adding an in-stadium DJ for games, and establishing a program-wide mantra of "rowing the boat".

The event raised funds for the Michigan Special Olympics, and led Holly Anderson of Sports Illustrated to proclaim Fleck as "the best new hire" for 2013, if only for generating interest in the program.

[26] By 2015, Fleck was one of seven FBS head coaches with NFL playing experience: Jim Harbaugh, Steve Spurrier, Jeff Brohm, Joey Jones, Kliff Kingsbury, and Kyle Whittingham.

[32] WMU lost 38–24 in the 2014 Famous Idaho Potato Bowl against the Air Force Falcons of the Mountain West Conference.

The matchup marked the first time that WMU had hosted a Big Ten Conference opponent since 2007 (Indiana) The following week, they lost to Georgia Southern 43–17.

[38] On December 6, 2016, Fleck was announced as one of five finalists for the Eddie Robinson Coach of the Year award alongside Colorado's Mike MacIntyre, Washington's Chris Petersen, Alabama's Nick Saban and Penn State's James Franklin.

[39] Following Tracy Claeys' firing, Fleck accepted the head football coaching job at the University of Minnesota on January 6, 2017.

[43] The defense improved dramatically, and the team won two of its last three regular season games against strong opponents, defeating Purdue (41–10), losing to No.

The Gophers' victory over the Badgers returned Paul Bunyan's Axe to Minneapolis for the first time since 2003, and earned the program its second trip to the Quick Lane Bowl in Detroit.

In Minnesota's first appearance in a bowl game under Fleck, the Gophers defeated the Georgia Tech Yellow Jackets 34–10 to finish the season 7–6.

By comparison, Minnesota's two winningest coaches, Hall of Famers Bernie Bierman and Murray Warmath, never won more than eight games in a season.

Due to the COVID-19 pandemic, the Big Ten Conference first made the decision in July to eliminate non-conference games for all fall athletics, limiting member teams to conference-only schedules.

In a Week 5 matchup against Purdue, the Gophers were forced to compete with a total of 22 players unavailable due to a combination of positive COVID-19 tests, contract racing, opt-outs, and injuries.

[57] To end the season, the Big Ten arranged for Minnesota and Wisconsin to play, marking the 130th meeting between the border rivals and allowing the longest-running series in FBS history to continue uninterrupted.

After back-to-back wins over Miami (Ohio) and Colorado, the Gophers dropped a 14–10 loss at home to Bowling Green, who entered the game as 30.5-point underdogs.

Kaliakmanis started the final three games of the regular season, a stretch that included wins over Northwestern and Wisconsin and a 13–10 loss to Iowa.

After improving to 2–0 with a non-conference win over Eastern Michigan, Minnesota went on to lose three of their next four games, including a 37–34 overtime loss to Northwestern in which the Gophers led 31-10 going into the fourth quarter.

[62] In 2014, Fleck was inducted into the Hall of Fame of Kaneland High School, his alma mater, in Maple Park, Illinois.

[63] Fleck credits Jim Tressel, Greg Schiano, and Jerry Kill (among others) with helping advance his coaching career.

[66][67][68] Fleck devised the "Row the Boat" mantra as part of his grieving process after Colt's death, and extended it to his coaching style.

After he left Western Michigan for Minnesota, Fleck and WMU were in a brief dispute over the intellectual property rights to the phrase, but they soon came to a settlement without resorting to the courtroom.

Fleck and UNRL apparel company collaborated to release a "Row the Boat" clothing line, with 14% of proceeds benefitting University of Minnesota Masonic Children's Hospital and Ronald McDonald House Charities.