He suffered the injury while bumping into teammate Rick Mahorn in yesterday's game against the Cleveland Cavaliers.
Philadelphia coach Jim Lynam said the early diagnosis was that Barkley will miss two weeks.
But team doctor Jack McPhilemy said the injury, which he called a second-degree tear, could end Barkley's season. A more definitive prognosis will be available after tests today, McPhilemy said.
76ers center Armon Gilliam said: "Charles leaves a big void. It's not a good situation, but we've been through it before. He means so much for the team."
Earlier in the day, Barkley said he didn't mean to hit anyone when he spat during a game last week.
Late in the fourth quarter of Tuesday's overtime loss at New Jersey, Barkley became angry at a courtside fan who he said had berated him all evening. Standing near the end line, the five-team All-Star turned and spat. Some apparently landed on the 8-year-old daughter of a longtime Nets season-ticket holder.
"For the record, I didn't spit into the crowd," said Barkley. "I don't know in my heart if I spit if it got on the little girl."
He added, "Regardless of what happened, I apologize to her and to everybody else."
Barkley was suspended one game without pay and fined $10,000 by the National Basketball Association.
"Sometimes the things I do are obviously wrong," Barkley said in a taped interview aired yesterday by NBC. "As for the spitting incident, that was totally wrong. It's just a stupid thing I did."
He tried to play down the incident, saying he "snapped" but added, "it's not like I killed somebody or beat him to a pulp.
"In the heat of the moment, I tried to spit on the floor and it accidentally got on somebody."
* NUGGETS: Less than 18 months after acquiring a 62.5 percent ownership stake in the club, COMSAT Video Enterprises is being forced to consider selling the team, a Wall Street analyst says.
The team, which has the NBA's worst record and attendance, faces a projected 1991 loss of $9.6 million, The Denver Post reported yesterday.
"We expect that operation [the Nuggets] to be disposed of in 1991," wrote Charles Schelke, a financial
analyst for New York-based Smith Barney, Harris Upham and Co., in a seven-page analysis of Communications Satellite Corp.
"There is a lot of pressure for [COMSAT executive Bob] Wussler to get out of the Nuggets. It doesn't make sense for COMSAT to own them, and secondly, the team's losing money," Schelke told the Post.
Wussler, insisting that COMSAT is happy with the team, said: "The Denver Nuggets are not for sale."
The Denver franchise became the first U.S. major-league team with significant black ownership in November 1989, when Peter Bynoe and Bertram Lee obtained 32.5 percent of the team. Their purchase, however, was possible only because NBA commissioner David Stern persuaded longtime friend Wussler to provide the major financial backing, the Post reported.
Wussler had envisioned the purchase of the Nuggets as live sports programming for pay-per-view audiences in hotels and as pTC COMSAT's entree into satellite broadcasting of games involving all NBA teams.
Neither project has gotten off the ground, and COMSAT now would like to get out of video entertainment, Schelke said.
* MAVERICKS: Forward Roy Tarpley, who was arrested early Saturday for suspicion of driving while intoxicated, denied yesterday that he was drunk and that he cursed and verbally threatened arresting officers.
"What good would that do me to fight the police? Let's be real about this," the 26-year-old basketball player said.
Dallas police said they would file a charge of driving while intoxicated against Tarpley today.
Tarpley said that, at the advice of his lawyer, he could not say whether he had been drinking before Saturday's arrest. But he denied that he was drunk.