He played college football for the Illinois Fighting Illini and was selected by the Kansas City Chiefs in the seventh round of the 2019 NFL draft.

Allegretti attended Lincoln-Way East High School in Frankfort, Illinois, a suburb of Chicago.

[9] He scored his first touchdown on a one-yard reception against the Pittsburgh Steelers in the Wild Card Round of the playoffs on January 16, 2022.

[13] After mostly being a backup throughout the season, Allegretti became the Chiefs starter for the AFC Championship Game and Super Bowl LVIII after Joe Thuney got injured.

His twins were born on the morning of February 12, 2023, the same day Allegretti won Super Bowl LVII, his second championship.