Guerendo was born in Clayton, Indiana[2][3] and attended Avon High School in Avon, Indiana. In his junior season, Guerendo hauled in 19 receptions for 596 yards and six touchdowns.[4] Guerendo had a breakout senior season bringing in 54 receptions for 1,258 yards and 16 touchdowns.[5] As a senior, Guerendo was named the Indianapolis Star's Mister Football for wide receivers.[6][5]
In Guerendo's first season in 2019, he carried the ball once for one yard, while also making one catch for three yards, and returning one kickoff for 49 yards.[9] In the COVID shortened 2020 season, Guerendo carried the ball 11 times for 36 yards.[10] In week two of the 2021 season, he recorded his first career touchdown on an 82-yard run versus Eastern Michigan.[11] Guerendo finished the 2021 season with 160 yards and a touchdown of 23 carries, while also racking up two receptions for six yards.[12] In 2022 he rushed for 385 yards and five touchdowns on 64 carries, while also notching 17 receptions for 115 yards and a touchdown.[13] After the conclusion of the 2022 season, Guerendo decided to enter the NCAA transfer portal.[14][15]
Guerendo finished his Wisconsin Badger career playing in 20 games carrying the ball 99 times for 582 yards and six touchdowns, while also notching 20 receptions for 124 yards and a touchdown.[16] He graduated from Wisconsin in December 2022 with a bachelor's degree in personal finance.[17]
Louisville
In 2023, Guerendo became a graduate transfer to the University of Louisville, playing for the Louisville Cardinals for his final season of college eligibility.[18][19] In Guerendo's Louisville home debut in week two of the 2023 season, he rushed for 63 yards and a touchdown on 11 carries, while also hauling in four receptions for 47 yards.[20] In week ten of the 2023 season, Guerendo had a career performance rushing for 146 yards and three touchdowns in a win over Virginia Tech.[21] In the 2023 Holiday Bowl, Guerendo rushed for a career high 161 yards and three touchdowns, on 23 carries, but the Cardinals lost to USC 42–28.[22] Guerendo finished the 2023 season with 810 yards and 11 touchdowns on 132 carries, while also making 22 receptions for 234 yards.[23] After the conclusion of the 2023 season, Guerendo declared for the 2024 NFL draft.[24][25]
Guerendo was drafted by the San Francisco 49ers in the 4th round (129th overall) of the 2024 NFL Draft.[28] In May, he signed a 4 year contract with the 49ers.[29] After injuries to running backs Christian McCaffrey and Jordan Mason,[30] he had some playing time, making his debut in week 2 against the Minnesota Vikings in a 23–17 loss. He had his first rushing touchdown in week 8 against the Dallas Cowboys, along with 102 rushing and receiving yards.[31]
Personal
Isaac was born in Indianapolis to Mario and Jennifer Guerendo. Mario is an emigrant from the Central African Republic, and Jen competed in track & field in high school.[5]