[5] He played with different regional and provincial teams, while attending high school at École secondaire du Versant in Gatineau, Quebec.

Aumont was 15 years old when his hometown Montreal Expos left for Washington, D.C. after the 2004 season, but still supported the team despite playing in a new location.

[6] Aumont appeared in 15 games in 2008 (8 starts) for the Seattle Mariners A level affiliate, the Wisconsin Timber Rattlers, posting a 2.75 ERA over 55+2⁄3 innings with 50 strikeouts versus 19 walks.

[7] He began the 2009 baseball season with the High Desert Mavericks, the Seattle Mariners Advanced A affiliate, where he was converted into a reliever.

In 29 appearances he posted a 3.24 ERA with 12 saves as the closer, earning a promotion to the Double-A West Tenn Diamond Jaxx in mid-July.

[8][9] Aumont played the 2010 season with the Advanced-A Clearwater Threshers and Double-A Reading Phillies, posting a combined record of 3–11, a 5.68 ERA, and 115 strikeouts in a career-high 122 innings pitched, mostly as a starter.

[7] He was moved back to a relief role for the 2011 season and made 43 total appearances for Double-A Reading, as well as the Triple-A Lehigh Valley IronPigs.

[7] Aumont began the 2012 season in the bullpen for Triple-A Lehigh Valley, posting a 3–1 record, 4.26 ERA, and 59 strikeouts in 44+1⁄3 innings pitched.

[14] After posting solid numbers in Triple-A, Aumont was called up on June 19, but struggled mightily with his control, walking 7 batters and serving up 2 home runs in just 4 innings.

[19] On June 7, 2017, Aumont came out of retirement and signed a one-year deal with the Ottawa Champions of the Canadian American Association of Professional Baseball.

[22] He finished the season with the lowest ERA (2.65) and fewest earned runs against (35) among all Can-Am League starters, and was named the 2019 Pitcher of the Year.

He then proceeded to retire MLB All-Stars David Wright, Kevin Youkilis, and Curtis Granderson in order, the last two by strikeout, to escape the inning with no runs surrendered.

Nonetheless, at 34 years old, in his first tune-up game before the 2023 World Baseball Classic, he pitched a perfect inning against the Seattle Mariners and his fastball reached 92 miles per hour.

Standing 6 feet 7 inches (201 cm) and weighing 255 pounds (116 kg), Aumont threw a fastball in the mid 90s, reaching the upper 90s on occasion, with late movement.

[30] In January 2023, just two months before the 2023 World Baseball Classic, Aumont broke his tailbone during a recreational ice hockey game at Carleton University.