As a freshman in 2020, Foster played in seven games where he made two tackles, while making no receptions.[3] In week 10 of the 2021 season, he made his first career start bringing in three catches for 33 yards versus Purdue.[4] During the 2021 season, Foster notched 12 receptions for 164 yards and a touchdown in three starts for the Spartans.[5] In 2022, Foster notched seven receptions for 98 yards and a touchdown.[3][6] In week 10 of the 2023 season, he tallied four receptions for 94 yards and a touchdown in a win over Nebraska.[7] In week 12, Foster brought in seven receptions for 94 yards and a touchdown in a win over Indiana.[8] During the 2023 season, he started in all 12 games for the Spartans, hauling in 43 receptions for 576 yards and three touchdowns.[9]