Fenroy attended St. Charles Catholic High School in Laplace, Louisiana prior to attending ULL. He earned Class 3A All-State honors as a senior with 1,580 rushing yards on 166 carries in the regular season a total that ranked 9th in the state among all five classifications. He rushed for 32 touchdowns in the 10-game regular season and had 34 total scores. Tyrell's 206 points in 10 games were second among all state players. Including the playoffs, he rushed for 2,100 yards and scored 44 TDs as a senior and did not fumble once all season. He was named MVP in District 10-3A each of his last two seasons. Fenroy was named Clarion Herald All-Elite Team/Offensive MVP. Overall, he finished his career with 4,320 yards rushing and 72 touchdowns and had 540 receiving yards and five receiving scores. On special teams, Tyrell piled up 854 kick return yards and five return touchdowns. Fenroy finished his prep career with 5,714 all-purpose yards and 82 touchdowns.
College career
Fenroy was named to the all Sun Belt Conference team each of his four seasons at Louisiana-Lafayette. He earned Second Team All Conference honors after his 2005 freshman year and First Team All Conference following the 2006, 2007, and 2008 seasons. He was honored with the Conference Player of the Year award in 2008. He ended his career as a Ragin Cajun with 4,646 yards and 48 touchdowns. He ran for a career-high and school record in rushing yards with 297 yards as well as 3 touchdowns on October 4, 2008 against the UL Monroe. Fenroy holds the all-time rushing record for Louisiana-Lafayette, the Sun Belt Conference, and the state of Louisiana Fenroy was honored as one of the top running backs in the nation his senior season by becoming one of ten semi-finalists for the 2008 Doak Walker Award. Fenroy became only the 7th player in NCAA Division I-A history to rush for four consecutive 1,000 yard seasons. Before the final game of his career, Tyrell had his jersey retired by the university, an honor reserved for players that have finished their career. Tyrell is enrolled back at ULL in order to finish requirements needed to obtain his degree in Criminal Justice.
Professional career
Pre-draft
In preparation for the 2009 NFL Draft, Fenroy ran a hand-timed 40 yard dash at 4.46 seconds and an average of 4.51 seconds. He had a 38-inch vertical jump and finished 18 bench press repetitions of 225 pounds.
Chicago Bears
After going undrafted in the 2009 NFL Draft, Fenroy signed with the Chicago Bears as an undrafted free agent on April 27. The Bears waived Fenroy on May 5.
On June 19, 2009, it was announced that Fenroy agreed to terms with the Calgary Stampeders of the Canadian Football League. However, on the following day, Fenroy informed The Advertiser that he was drafted by the Las Vegas Locomotives of the upstart United Football League. Fenroy said of the situation of being a member of two teams, "I was drafted by the Las Vegas team today, and their running back coach called me today. So if the CFL doesn't come up with a bigger deal, I'm heading there." Fenroy decided to go to the UFL over the CFL on June 22, and his signing was announced on August 31.
