Hall was called for slashing after he was hit hard by Senators defenseman Eric Gryba at 11:04 of the period. He came out of the penalty box and stayed on the ice briefly before going to the dressing room with 6:42 left in the period.
The Canadian Press reported that Hall left following the game with his knee in a brace but without using use of crutches.
"I know it's his knee," coach Dallas Eakins said after the Oilers' 3-1 victory. "I don't know the severity of it. Our doctors will look at it and let us know. When a guy doesn't come back in the game, usually it's something that's going to be more than a day or two. But I have no idea right now."
Hall, the first pick of the 2010 NHL Draft, has three goals and five assists in nine games.