Barring some unforeseen change over the next two weeks, Boris Diaw is the Charlotte Bobcats' opening-night center.

And his backup, Gana Diop, acknowledged he's 25 pounds overweight and way behind in preparing for the season.

That's the upshot, after free-agent center Kwame Brown took a one-year, $7 million offer from the Golden State Warriors Tuesday.

It's safe to say what the Warriors paid far exceeds what the Bobcats were willing to offer Brown, who started the second half of last season and thrived under coach Silas (7.9 ppg, 6.8 rpg.) Sources indicate the Bobcats balked at the suggestion Brown was worth $5 million a season.

Diaw, at 6-foot-8, 245 pounds, is best known for his versatility. But it could be a reach to ask him to play 35 minutes a night guarding the likes of Orlando's Dwight Howard and Milwaukee's Andrew Bogut.

"I've always been that kind of player who'll play wherever you need me," Diaw said after practice Tuesday, as news broke that Brown wouldn't be back. Diaw said he might have to add weight to pound with centers on a regular basis.

That leaves 7-footer Diop as the only true center on the roster and the presumed backup. He said Tuesday he weighs about 305 pounds, 25 above his playing weight last season. He's never had great impact (2.1 points per game, 3.8 rebounds per game for his NBA career) and costs the Bobcats about $7 million per season.

"Last year coming into camp I was way ahead of where I am now," said Diop, who could play only spot minutes at this juncture, according to coach Paul Silas.

The Bobcats have experienced a radical rebuild since the end of the 2009-2010 season. Since then point guard Raymond Felton, center Tyson Chandler, small forward Gerald Wallace, shooting guard Stephen Jackson and Brown have all departed. The Bobcats are starting over with rookies Kemba Walker and Bismack Biyombo and young players D.J. Augustin, Tyrus Thomas and Gerald Henderson.

If there's any plus to this, it probably opens possibilities for featuring Thomas at power forward. Thomas signed a big contract with the Bobcats two summers ago, but has been playing behind Diaw at power forward.

Brown will be missed for his 6-11 size and the strength and persistence to play rugged post defense. Tuesday Diaw called Brown "precious, particularly at the defensive end."

Now they'll be improvising in the middle, particularly until Diop regains enough conditioning to play regularly. He had surgery last January to repair a ruptured Achilles tendon, and was not cleared for full physical activity until about six weeks ago.

Beyond Diop, the other alternatives behind Diaw at center are veteran Eduardo Najera or Biyombo - once Biyombo resolves a contract dispute with his former Spanish team.

Diaw played some center as a Phoenix Sun, but that was in an extremely high-speed system where every starter was undersized.

Diaw, entering the final season on his current contract, said center and power forward are "totally different...You get tired by just pushing (centers), rather than running around."

Silas intends to run some sets that force opposing centers to leave the lane, chasing Diaw away from the basket and into screens. Diaw is a gifted passer and outside shooter, so there is some compensation at the offensive end.

Still, Diaw knows this is far from ideal.

"If you look at the teams going deep in the playoffs," Diaw said, "you need a real center."