Watch: Celtics fans shower Simmons with 'Not a rookie' chants

One of the leading candidates for NBA Rookie of the Year apparently shouldn't qualify for the award, according to the over 18,000 in attendance at TD Garden on Monday night.

As Ben Simmons of the Philadelphia 76ers stepped up to the charity stripe late in the third quarter during Game 1 of the Eastern Conference semifinals, a deafening "Not a rookie" chant echoed throughout the arena courtesy of Boston Celtics supporters.

Simmons was drafted first overall in the 2016 draft but is eligible for this year's hardware as a result of sitting out his entire rookie season with a broken right foot.

Utah Jazz guard Donovan Mitchell has made his views known on who should qualify for Rookie of the Year and seemingly enjoyed the Bostonians having some fun at Simmons' expense.