Hall sat out Tuesday's game against the Columbus Blue Jackets after cutting his head when he accidentally made contact with a teammate during pre-game warm-ups.
The 20-year-old slipped on the ice and collided with a teammate before cutting his head on the skate of another Oilers player.
"He's doing much better. Swelling has gone down, he's got a clear head, he had a good night's sleep," Renney said Wednesday in a video post on the Oilers' website. "All that being said I would call it doubtful for (Thursday), which I don't think would surprise anyone. If you talked to Taylor he would say he's hopeful, but we'll see."
Hall, who was not wearing a helmet, had blood running down the side of his head while a trainer tried to staunch the flow.
The first overall pick in the 2010 draft, Hall has 15 goals and 16 assists in 36 games. He was facing the Blue Jackets for the first time since a March 3 game in which he broke an ankle during a fight with Derek Dorsett.
Hall was on a roll with goals in six of his past nine games.
It was just another bit of bad news for the Oilers, who were already missing their top two scorers, winger Jordan Eberle (right knee) and centre Ryan Nugent-Hopkins, their second-leading scorer and the NHL's top rookie (left shoulder) along with centre Eric Belanger (back) and defencemen Ryan Whitney (right ankle), Tom Gilbert (right knee), Cam Barker (left ankle surgery), Taylor Fedun (broken right leg) and Alex Plante (head).