Los Angeles may be the land of sunshine and movie stars, but for Lakers fans, the past year has contained an awful lot of doom and gloom.

After a one-sided dismissal in the first round of the playoffs by Phoenix, the summer passed with Kobe Bryant issuing a trade demand, then kinda-sorta, but not really rescinding it. He never quite owned up to whether he still wanted out or not as he watched training camp and the first half of the season play out. Meanwhile in the offseason, Bryant managed to be caught on tape making scathing remarks about young center Andrew Bynum, and denigrating L.A.’s unwillingness to trade him to New Jersey for Jason Kidd last February.

If only Kobe had been the Lakers’ GM, because that would have been one heck of a trade for the Nets. Bynum has blossomed into one of the best big men in the West, averaging 13.1 points, 10.2 rebounds, 2.1 blocks, and shooting 63.6% from the floor. Those numbers have been even better more recently: Since December 1, the 20-year-old center is averaging 15.1 points, 10.1 boards, and shooting a scalding 67.0%, and the Lakers have gone 17–4 in that time span to take over first place in the Pacific Division.

So sunny was the outlook that Bryant, of all people, recently said “We’re a championship caliber team when [Bynum] is in the lineup.”

Sadly, he could only force those words out after Bynum was already out of the lineup. He suffered a partial dislocation of the patella and a bone bruise of his left knee on Sunday that will keep him out of action for two months, a span in which the Lakers play 27 games. It’s a rough 27 games, too — L.A. only has three home games in February, for instance, and has already played half its complement of games against the weaker East.

Even when Bynum comes back, there’s no guarantee that the big fella will be able to do what he’s done for the past two months. Bynum is huge — 7 feet, 275 pounds — and as a result, he’s going to struggle to maintain his conditioning while he can’t move around on the knee. Additionally, there are the obvious questions of regaining timing and chemistry to consider once he returns, all of which makes one wonder if we’ll see Bynum attain such a lofty standard of play again this season. It’s possible we’ll have to wait until the fall.

Thus, the brief ray of sunshine in Lakerland has been obscured by another cloud. It’s a shame because it blemishes one of the league’s most improbable stories. The reason Bryant had made his trade demand in the first place was because he didn’t think the Lakers’ supporting cast was good enough for the team to contend, and that the club was wasting the best seasons of his prime by pairing him with a substandard crew.

He was not alone in this opinion. Most commentators, including this one, felt that Bryant’s great talent might lift the Lakers to a playoff spot, but anything beyond that would be pure fantasy in the loaded Western Conference.

So, Bryant showed up for training camp, went through the motions, and made enough of an effort in the games that nobody could accuse him of mailing it in. Besides, he had to stay somewhat sharp for when he got his wish and was traded to a contender — you know, somebody such as Chicago or Houston.

Of course, that entire premise now seems hysterical. The Lakers went into yesterday’s game owning the best record in the West at 26–11, and the supporting cast was the main reason. The development of young players such as Bynum and Jordan Farmar, the acquisitions of point guard Derek Fisher and ex-Knicks member Trevor Ariza (sorry Knicks fans, but you knew there was a dagger coming at some point), and the continued steady play of forwards Lamar Odom and Luke Walton, combined to give the Lakers one of the best supporting casts in basketball.

Ironically, Bryant had only just begun to realize what he had when it was taken away in the form of Bynum’s injury. No, this doesn’t mean the Lakers are suddenly going to lose all their games. But it does hurt when you look at the razor-thin margin separating the top teams in the West. Despite its momentary perch atop the conference standings, L.A. is only five games ahead of ninth-place Utah, and the 10-team race for the conference’s eight playoff spots is so tight that it’s very possible all 10 teams will finish between 48 and 56 wins for the season.

Let’s do the math. If the Lakers go, say, 15–12 in their 27 games without Bynum, it would leave them at 41–23 when he returns, and it would still put them on pace for a win total in the low 50s. That seems reasonable, given that L.A. still has plenty of frontcourt depth (Kwame Brown, Chris Mihm, Ronny Turiaf) and might purchase more in the coming days (the names of P.J. Brown and Chris Webber have come up).

Thus, losing Bynum doesn’t necessarily ruin the season. But what it does do is hurt their hopes of gaining one of the top seeds in the West, thus requiring them to run an unlikely gauntlet in the playoffs. For instance, it’s almost impossible for L.A. to get a top-four seed unless they win the Pacific, because the other two division winners are guaranteed a spot, and the runner-up between Dallas and San Antonio in the Midwest is almost certain to have the other slot.

That puts them fighting with the Hornets and perhaps one or two other teams for the fifth seed in the conference. In the big picture, that could mean another rematch with Phoenix in the first round — and another first-round exit.

But before we reach that point, there’s still one card that remains unplayed: Kobe. He’s mostly avoided the kind of scoring explosions he put up in past seasons, and as a result, his Player Efficiency Rating (PER, my per-minute rating of a player’s statistical effectiveness) is down to 25.0 after being 26.1 and 28.1 the past two seasons. Yet in the team’s first game without Bynum, he showed what he can do when the situation demands, scoring 48 points in an overtime win over Seattle on Monday.

As a result, the big question L.A. began the season asking will be turned on its head for the next eight weeks. We no longer have to wonder whether the Lakers’ supporting cast is good enough for a star such as Bryant to contend for a title. Rather, we can see whether Kobe has the goods to lift such a team when one of the key cogs is out of action.

jhollinger@nysun.com