So much for NBA fans forgetting about Grayson Allen's checkered on-court history in college. The Memphis Grizzlies guard was ejected from his team's Summer League game against the Boston Celtics on Thursday after picking up a second flagrant foul.

The deciding call came after Allen hit Celtics rookie Grant Williams in the head while contesting a shot in the paint.

In a vacuum, there's an argument to be made that Allen made contact with Williams' head accidentally. But context of his well-documented history at Duke of tripping opposing players, coupled with Allen clearly taking exception to a legal back screen from Williams just seconds before the play in question, makes his intent obvious.

So does the fact that Allen was called for another flagrant foul just minutes earlier, reacting to an innocuous flare screen from Williams by shoving him in the head from behind.

Allen had three points on 1-of-8 shooting before being ejected. Williams, the No. 22 overall pick of the 2019 NBA Draft,  scored 21 points and grabbed seven rebounds, connecting on 4-of-5 from deep while continuing to reign as a plus-minus superstar in Summer League.

Grayson Allen was traded from the Utah Jazz to the Grizzlies last month, along with Jae Crowder, Kyle Korver, and a protected first-round pick, in the deal that sent Mike Conley to Utah. The No. 21 overall pick last year, he saw little playing time as a rookie, averaging 5.6 points in 10.9 minutes per game over 38 appearances. But Allen showed out in the regular season finale, a game Utah wasn't trying to win, by scoring 40 points, perhaps increasing his trade value in the process.