Cassell sits this one out with back spasms

MILWAUKEE - Celtics guard Sam Cassell has back spasms, but he also said he will be back soon.

The 38-year-old Cassell, who acknowledged a history of back problems, missed his first game last night since joining the Celtics March 4.

Coach Doc Rivers said Cassell wouldn't play tonight at Washington and wasn't certain when he would play again in the regular season. But Cassell said it's not a major injury.

"I'll be ready for the postseason," he said.

The 6-foot-3-inch, 185-pounder is averaging 5.3 points and 1.7 assists in 13 games with Boston. Cassell missed 12 games when he was with the Clippers earlier in the season with a strained left calf, but he had no other major injuries.

Cassell said he hurt the back while taking a charge on Bobcats guard Raymond Felton during Saturday's win. He said he was hurting during Monday's practice in Charlotte and he was walking gingerly yesterday.

When asked if he could have played last night if it was a postseason game, Cassell said, "If I had to I could definitely do it . . . a couple of Advil."

A happy Pierce

Forward Paul Pierce met the team here Monday after being away since Friday following the birth of his daughter.

Pierce said the birth "was a great day in the Pierce household." He's already changed diapers and joked that he's getting better sleep on the road.

"I didn't have no rest [at home]," he said. "No sleep. No day off. This is rest right here."

"I just told him congratulations," said Rajon Rondo, who has an infant daughter. "I'm new myself. Ray Allen gave him some advice."

Pierce also made sure teammates and media got an earful about his alma mater, Kansas, winning the NCAA Tournament Monday against Memphis.

"I heard him in the [hotel] hallway, at breakfast, and on the bus," Allen said.

A sounding board

Rivers said he was only a "sounding board" in Marquette's recent men's basketball coaching search. The ex-Marquette star is on the school's board of trustees and usually attends two of four meetings per year.

Brent "Buzz" Williams was promoted from assistant to head coach Monday, replacing Tom Crean, who departed for Indiana.

Rivers attended Williams's introductory news conference.

"For the most part I try to stay out of it," said Rivers. "I don't know the college scene that well. I just know who I know and I do have the ability to make calls."

When asked if he ever considered coaching in college, Rivers said, "I had an opportunity, not at Marquette, four years ago. I'm not even going to say the school and I told them, 'No thank you.' I don't want to recruit. Someday maybe. I love college basketball, but not right now.

"I don't ever want to go where my kids are playing or where my kids are being recruited. I think that would be an awful pressure. Your son has to make a choice and you're a college coach? I'd never do that to them."

The eldest of Rivers's sons, Jeremiah, is a guard for Georgetown. He considered going to Marquette, but the pressure of following in his dad's footsteps caused him to go elsewhere.

"He loved Marquette, he loved Tom Crean," Rivers said. "But he walks in the building and sees my Hall of Fame thing and you walk in the arena and my banner is hanging there. He was like, '[Wow], I don't want all that.' I agreed with him."

Scouting in all ports

Director of basketball operations Danny Ainge is attending the Portsmouth Invitation Tournament, showcasing the top "under the radar" college seniors, which begins today in Portsmouth, Va. UMass forward Gary Forbes and Rhode Island guard Parfait Bitee are slated to play. URI forward Will Daniels turned down an invite . . . The ratings of Comcast SportsNet's Celtics telecasts are up from last season. Through 69 telecasts, Comcast's games are averaging a 3.5 rating (80,500 households) vs. a 1.7 through 69 games in 2006-07.

Marc J. Spears can be reached at mspears@globe.com