Ariza to sit out about eight weeks

Forward Trevor Ariza will sit out about eight weeks because of a broken bone in his right foot, an event that further depletes the Lakers’ frontcourt.

It was enough to make Coach Phil Jackson sigh when he was asked about the recent rash of injuries.

“Yep, it’s going to be one of those things,” he said. “We just have to work our way through this. Unfortunately for Trevor, he was playing really well.”

Since the inception of the active-inactive list before the 2005-06 season, the Lakers have had only three games in which every player was available for consideration for the 12-man active roster.

Ariza became a fixture on the Lakers’ second unit after being acquired from Orlando in November. He was averaging 6.5 points and 3.5 rebounds in 18 minutes a game.

He also started three games and had been an active defender for the Lakers, who liked his length and speed.

Ariza said he was injured after coming down on Derek Fisher’s foot while going up for an offensive rebound at Sunday’s practice.

“My foot kind of just rolled and kind of just cracked,” Ariza said. “I guess that’s what just happens when you’re competing every day.”

Ariza’s absence will probably mean more minutes for Luke Walton, who was averaging 7.6 points, 3.6 rebounds and 3.1 assists in 25.4 minutes a game before Monday.

There are two other scenarios. The Lakers could play Kobe Bryant more often at small forward, which would mean more time in the backcourt for Sasha Vujacic. Or Lamar Odom could play more at small forward, which would mean more time for Ronny Turiaf at power forward.

The Lakers are already without Andrew Bynum for at least seven more weeks and Chris Mihm for at least another week, although probably longer than that.

Mihm finished the third of three weekly sonar-wave ankle treatments on his right foot, and could be back in time to play part of the Lakers’ nine-game trip that begins Jan. 31 in Detroit.

“It’s still hard to tell until he gets on his feet and starts doing weight-bearing things,” Jackson said.

--

The Lakers signed center DJ Mbenga to a 10-day contract, giving them some added brawn up front.

Mbenga, 27, was waived by Golden State two weeks ago in a minor cost-cutting move.

The move brought the team to a league-maximum 15-player roster and signaled the apparent end of Chris Webber’s chances of joining the Lakers.

The Lakers were concerned about Webber’s conditioning and with the way he faded in last season’s playoffs. Webber has not played since the Detroit Pistons lost to the Cleveland Cavaliers in the Eastern Conference finals. He averaged 9.9 points and 6.3 rebounds in 16 playoff games last season for Detroit.

Mbenga, a 7-footer from Congo, averaged 1.2 points and 1.9 rebounds in 16 games with Golden State.

Jackson said he hoped to get solid defense and rebounding out of Mbenga, who was described by Jackson as a “big guy in there who can block some shots and do some things.”

Mbenga spent the first three seasons of his career with Dallas. His best season was 2005-06, when he averaged 1.7 points and 1.3 rebounds a game.

Mbenga had a relatively active game against the Lakers in the Warriors’ 113-103 loss Dec. 9 at Staples Center, hitting season highs with seven points and four rebounds.

--

Undrafted rookie Coby Karl suited up against the Denver Nuggets . . . and his father.

Karl was with the Lakers’ Development League team the first two times the Lakers played the Nuggets, who are coached by George Karl.

“It’s really not too big of a deal to us,” Coby Karl said. “It’s fun to have him in town and play against him, but I think it’s a better story to write about than anything. It’s not just another game, but in essence, it is just another game.”

Karl played the final 3 minutes 19 seconds Monday, scoring one point on a technical-foul free throw.

--

mike.bresnahan@latimes.com