Dalembert elbowed Valanciunas with 10:59 to play in the third quarter as he battled the Raptors big man for position.
Referees ruled that Dalembert committed a flagrant-2 foul and he was ejected from the game.
The NBA reviews all flagrant foul calls and can fine or suspend a player based on its interpretation of the intent of the action.
Dalembert has had an inconsistent role with the Knicks this season. Obtained in July as part of the Tyson Chandler trade, Dalembert has averaged 3.8 points, 5.3 rebounds and 1.2 blocks in 17 minutes per game.
He has started 20 of 30 games but was recently taken out of the starting lineup by coach Derek Fisher amid the Knicks' struggles.
At 5-25, New York is off to the worst start in franchise history through 30 games.