Chris Paul was scratched from a second-straight crucial game in the Hornets' quest to remain in the playoff hunt when he was ruled out from Wednesday night's matchup against the Dallas Mavericks.
Hornets coach Monty Williams said he could not project a return date for his All-Star point guard, who is being monitored daily by a neurologist hired from outside the team.
"It's up to the doctors," Williams said. "He feels good. He's progressing the way that they want him to, but it's one of those things that they don't want to mess around with."
Paul has been out since his collision with Cleveland's Ramon Sessions during New Orleans' victory over the Cavaliers on Sunday night.
Paul attended the Hornets' shootaround on Wednesday morning wearing practice gear, but Williams said he only watched and rode a stationary bike. He went straight to the Hornets' locker room afterward without speaking to reporters.
Paul is averaging 15.9 points and 9.6 assists for the Hornets, who entered Wednesday's action clinging to the seventh out of eight playoff seeds in the Western Conference, with ninth-place Phoenix only two games behind.
While Paul is out, Jarrett Jack will start at point guard.
Jack, acquired last November in a trade with Toronto, has been on one of his most productive stretches of the season lately, averaging 18.8 points in his last five games, including 23 points in a start at Chicago on Monday night.
"He's played well," Williams said. "He's defending top guys. He's used to it. He's been a starter in this league so he knows what he's got to do to carry a team and run a squad. It's good to have a guy like Jarrett."
The Hornets also hoped to get a boost from the possible return of small forward Trevor Ariza, who has missed three games with a groin strain but practiced with the starters during Wednesday morning's shootaround.
Williams said he would decide Ariza's status shortly before Wednesday night's game, but Ariza sounded confident of his return.
"I'm feeling better. I'm going to give it a go tonight and see how things go," said Ariza, who is one of the Hornets' top one-on-one defenders and is averaging 11 points and 5.4 rebounds. "This is one of those injuries where if you don't take care of it, it will linger.
"It's tough, man, because we are in a position where every game counts," Ariza continued. "It's a tight race, but you've got to take care of yourself, so if we do get into the playoffs it won't keep lingering."
Meanwhile, the Hornets decided to add at least some depth to their backcourt in Paul's absence by signing Jerel McNeal to a 10-day contract.
The 6-foot-3 McNeal, a former Marquette standout, has played in 40 games with the Rio Grande Valley Vipers of the NBA Development League, averaging 19.5 points, 4.5 assists and 4.2 rebounds per game.
Williams said he did not expect McNeal to play right away but to be ready if needed.