Andrew Bynum suffered a hyperextended right knee after stepping on the foot of San Antonio’s DeJuan Blair while running back on defense in the second quarter of tonight’s game against the Spurs. Bynum will undergo an MRI exam Wednesday morning and will not join the team for its trip to Sacramento. He stayed on the court for quite some time before leaving the game and heading for the Lakers’ locker room with 8 minutes, 11 seconds left in the first half. He walked slowly, but under his own power. Joe Smith, a seldom-used big man, entered the game and grabbed two rebounds.

Bynum had surgery on his right knee July 28 to mend torn cartilage and missed the season’s first 24 games. He has had knee trouble in four consecutive seasons. He sat out of the 2008 playoffs after injuring his left kneecap and the Lakers fell to the Boston Celtics in the NBA Finals. He was relatively healthy in the last two seasons and the Lakers defeated the Orlando Magic in the 2009 Finals and the Celtics last June.

Matt Barnes, a backup forward, has a sore right knee and might not be able to play in tonight’s game against the San Antonio Spurs, the Lakers announced this afternoon. Barnes had surgery on his knee back in January. Steve Blake, a reserve guard, definitely won’t play tonight after coming down with chicken pox.The Lakers said he’s out indefinitely.

The Lakers plan to sign shooting guard Trey Johnson from the Bakersfield Jam of the D-League in order to bolster their playoff roster. Johnson was due to arrive at Staples Center during tonight’s game against the Spurs. He will sign Wednesday and be available to play in the regular-season finale against the Kings at Sacramento.

The league took another look at the technical foul assessed to Kobe Bryant for his part in a minor entanglement with Kendrick Perkins of the Oklahoma City Thunder in the first half Sunday and then decided to rescind it today. Bryant has 14 technical fouls this season. If he picks up two more in the Lakers’ final two games he would have to serve a one-game suspension to start next season. They don’t carry over to the playoffs.

Andrew Bynum wanted a full-court scrimmage today to help iron out the Lakers’ problems. So did Lakers coach Phil Jackson. It didn’t happen because they didn’t have enough healthy bodies. Steve Blake was out sick. Matt Barnes is still recovering from right knee surgery and needed a break. Kobe Bryant, Derek Fisher and Pau Gasol needed rest. Devin Ebanks isn’t ready to go after suffering a stress fracture in his left leg. Derrick Caracter is on assignment with the Bakersfield Jam of the D-League. Sooooo…. No scrimmage.

The Lakers got lost on the home stretch and didn’t play any defense to speak of from start to finish and fell for the fifth consecutive game, their longest skid since 2006-07. They are tied with the Dallas Mavericks for second place in the Western Conference with matching 55-25 records. The Oklahoma City Thunder is one game back at 54-26. The Lakers have games Tuesday against the San Antonio Spurs and Wednesday against the Sacramento Kings in order to get things right before the playoffs start next weekend.

Will they?

“I told them (Saturday) I didn’t think we would be able to turn it around in one game,” Lakers coach Phil Jackson said. “We got partially back into what we’re trying to do. A number of things went wrong for us (and) we didn’t survive.”

Said Derek Fisher: “We’re going to have some great stretches, some bad stretches and I think this one is tough for us in terms of how we want to finish the regular season. … We can’t get caught up in the way the package is supposed to look. At the end of the day, we just want to have the gift that we want and that’s to be champions.”

Said Lamar Odom: “We’ll fit it and find a way.”

Said Kobe Bryant: “We’ve got to focus on it (Tuesday’s game against the Spurs) and come out and do our jobs, which we haven’t been doing. We’ve got to do our jobs.”

The Lakers played with more fire, more passion, more desire tonight in the first half than in any of their last four games. Now, about their defense … Kobe Bryant scored 22 points, Pau Gasol had 18 and Andrew Bynum scored 10 points and grabbed five rebounds. Russell Westbrook had 18 points and Kevin Durant had 15 for Oklahoma City, which shot 62.2 percent (23 of 37). The Thunder also made 6 of 9 3-pointers. The Lakers never led and trailed by as many as 12 points before getting close by halftime. Oh, and Kendrick Perkins scored two points and grabbed two rebounds in his first game with the Thunder against the Lakers since he was traded from the Boston Celtics in February.

Power forward/center Pau Gasol had his say today when asked about Kendrick Perkins of the Oklahoma City Thunder, who said last month that he doesn’t like Gasol because he’s “soft” and dislikes Lakers coach Phil Jackson because he’s “arrogant.”

Said Gasol: “Certain players talk too much. They should worry about their own stuff.”

For the record, Gasol is averaging All-Star statistics of 18.7 points on 52.8 percent shooting plus 10.2 rebounds in 79 games this season. Perkins is averaging pedestrian totals of 6.3 points on 51.6 percent shooting plus 8.3 rebounds in 26 games.

Gasol also has two championship rings and Perkins has one.

PORTLAND, Ore. — Brian Shaw has always appeared to be the odds-on favorite to replace Phil Jackson when he retires from coaching at season’s end. Neither of them has spoken publicly about the possible transition during the summer, but Kobe Bryant did on Friday in an interview with a reporter from Yahoo! Sports.

“I feel all of the players believe in coach B-Shaw,” he said. “We have such a rapport with him. He’s been with us for such a long time. We all have a bit of a bias towards him. I don’t want to get in the way of management. But we’ve all kind of had our eye on him for a while.”

Bryant also said: “He’s been around Phil for a long time,” Bryant said. “He has a great deal of knowledge and understands the game. He communicates very well. He’s tough. I think when his time comes he’ll be ready. We go way back (as Lakers teammates in the early 2000s). It’s an honest relationship. What I mean by that is he doesn’t tell you what you want to hear. He tells you what you need to hear. That’s something I respect in people. I don’t like (butt) kissers. Never have. I have a great deal of respect for him.”

Bryant said the decision would be up to Lakers management, however.

“It’s not my responsibility to do that,” Bryant said. “It’s their responsibility to come to me and say, ‘What do you think about X, Y and Z?’ I’d be more than happy to give my opinion. I’m not just going to march up there and say, ‘Do X, Y and Z.’ If they want my input, they know where to find me.”

PORTLAND, Ore. — The Lakers lost their fouth in a row, tying their longest skid of the season, when they tumbled tonight against the Portland Trail Blazers. The Lakers weren’t aggressive and the Trail Blazers were and it showed in the final score. Kobe Bryant scored 24 points on 10-for-25 shooting. LaMarcus Aldridge had 24 points and 11 rebounds for Portland, and Gerald Wallace added 19 points and 13 rebounds. All five of Portland’s starters scored in double figures.

Coach Phil Jackson blasted the Lakers after the game.

“We were lazy and inefficient in the first half,” he said. “In the second half, we just didn’t buckle down and do the right thing offensively. … These guys just don’t want to play hard right now. … It’s a product of not paying attention, not being focused, not playing the game with the right attitude. … I asked them (the players) to give some recognition to what this is about, this job, their professionalism and their responsibilities.”

PORTLAND, Ore. — The Lakers were halfway to their fourth consecutive loss after a poor defensive effort tonight against the Portland Trail Blazers, a possible first-round playoff opponent. The Trail Blazers made 22 of 40 shots (55 percent) in the half, including 13 of 20 during the second quarter (65 percent). Kobe Bryant countered by hitting four consecutive 3-pointers in the closing moments of the second quarter to help the Lakers trim a 12-point deficit to six by halftime. Bryant scored 18 points on 7-for-13 shooting..