Stewart Berg, the fan who was involved in a confrontation with Celtics forward Antoine Walker, filed an application for a complaint yesterday at Boston Municipal Court. As a result, a probable cause hearing will be held June 11.

Whether or not Walker chooses to speak, he is required to appear for the hearing. Walker spends much of the offseason in Chicago.

After the hearing, the clerk magistrate will decide if charges are warranted.

The incident occurred May 9 at the FleetCenter. Throughout Game 3 of the Eastern Conference semifinal series between the Celtics and New Jersey Nets, Berg heckled Walker, calling for Celtics coach Jim O'Brien to take Walker out of the game. Once Walker exited the contest late in the fourth quarter, he walked toward Berg and confronted him.

The Celtics signed coach Jim O'Brien to a two-year extension yesterday, which means he is now under contract for the next three seasons. Although terms of the deal were not disclosed, sources close to the team said O'Brien will be paid $3 million per year when the extension goes into effect for the 2004-05 season. O'Brien will earn $1.5 million next season.

O'Brien anticipates his entire coaching staff will return for next season. Executive director of basketball operations Danny Ainge said completing new contracts for the assistants was his ''next order of business'' and he also anticipates ''no problems of having the entire staff back.'' According to Ainge, the determination to give O'Brien a two-year extension came after a brief, but intense period of evaluation. No other coaches were contacted.

The Boston Celtics announced today that they have extended coach Jim O'Brien's contract through the 2005-2006 season.

O'Brien's contract was set to expire at the end of this coming season, but Danny Ainge stated last week that he intended to keep the coaching staff in place.

O'Brien took over as Celtics head coach in 2000-2001 when Rick Pitino resigned with a 12-24 record.  O'Brien coached that Celtics team to a .500 record the rest of the season, earning another season as head coach.  He rewarded Celtics management for their faith by leading the Celtics to the Eastern Conference finals in his first full season as Celtics coach.  O'Brien has a career record of 117-95.

Celtics executive director of basketball operations Danny Ainge said yesterday he has granted permission for general manager Chris Wallace to talk with the Portland Trail Blazers. Wallace had dinner with Portland coach Maurice Cheeks Monday in Los Angeles, where Cheeks was taping an appearance on ''The Tonight Show with Jay Leno.''

Portland president/general manager Bob Whitsitt resigned after his team exited the playoffs in the first round earlier this month, and since then, a number of candidates have expressed interest in the job. Although Wallace has not asked for permission to speak with teams other than the Blazers, Ainge said he would not hesitate to grant it.''I think that he would like to look and see what options are out there,'' said Ainge. ''I think he would like to run a team on his own. But we will welcome him back if that opportunity is not there.''Reached yesterday on his cell phone, Wallace offered ''no comment'' on the Portland job. ''I'm still under contract with the Celtics and eager to jump into work with Danny and get going on our final preparations for the draft,'' said Wallace. ''We're in the backstretch with five weeks to go. The visits have begun, and that's very important.''

Phil Jackson will have to wait at least another year if he hopes to coach a record 10th NBA champion, breaking his tie with Red Auerbach, who won nine as coach of the Boston Celtics.

And don't think the old guy with the stogie isn't breathing a sigh of relief.

Interviewed on the Dan Patrick Show on ESPN Radio, Auerbach was asked if he rooted against Jackson and the Lakers.

"Absolutely," he said.

In some circles it's going to look like a status quo decision, or action by inaction.

But if Danny Ainge really wants to get to the meat of the challenge facing the Celtics over the next year - finding talent with low draft picks and no cap space - then signing coach Jim O'Brien to an extension and accepting the fact that Antoine Walker wasn't going anywhere are indeed the first steps.

Ainge would love to pare down the salaries on this team, but faces one immovable boulder of a problem.

In Walker, Paul Pierce and Vin Baker, he has three maximum salaries and only two maximum performance players.

Phil Jackson's trash, in the form of his most difficult Lakers season, is another man's treasure.

That man is longtime Boston Celtics coach Red Auerbach.

Jackson failed in his bid for a 10th NBA coaching championship, which would've broken his tie with Auerbach. On ESPN Radio on Friday, Auerbach said he rooted against Jackson.

"Doing it with one team is tougher," Auerbach said. "He (Jackson) waited for a great team to take over. That's not as much of a challenge as building one yourself."

The Celtics will not wait until training camp to learn whether Vin Baker will be able to contribute to the team next season. Team sources said this week Baker is expected to work out with the team in the minicamp preceding summer league in July.

If Baker does well enough there, he could participate with the Celtics entry in the Shaw's league at UMass-Boston.

The Celts have no way of knowing at this time whether Baker's sobriety will mean he can return to anything near the level of competency he showed before his habits began affecting his game.

Tony Battie underwent surgery Thursday at New England Baptist Hospital to repair a torn lateral meniscus in his right knee.

The Celtics center was expected to begin physical therapy yesterday. Recovery should take 4-6 weeks. The operation was performed by team doctor Arnold Scheller.

Throughout the season, Battie was bothered by a sore and swollen knee. The torn meniscus (cartilage) was at the root of the problem, though Battie played through the injury. He was unable to practice much during the regular season. He also needed to take time off after back-to-back sets and could not complete stretches of four games in five nights.

The Celtics announced that Tony Battie underwent surgery Thursday on his right knee for a torn lateral meniscus. Team physician Arnold Scheller performed the procedure with assistance from Lampros Minos.

Battie, who missed 11 games because of problems with the knee, was scheduled to begin his physical therapy program yesterday.

The center left the Celtics' 110-101 double-overtime loss in Game 4 against the New Jersey Nets Monday after bruising his knee once again.