CHICAGO -- Luol Deng sauntered into the locker room before one of the Bulls' final regular-season matchups looking relaxed, donning a gray pullover, black compression shorts and long socks that sprouted from his flip-flops. He plopped in front of his locker for a moment, lacing up his sneakers while chatting with a reporter. His glowing white smile matched the freshly cleaned jersey behind him. He stood up and glanced at Carlos Boozer sprawled across the floor, completely absorbed in game tape, and casually strolled out the door. He was loose. He was ready to play.

This has become a familiar scene as the Bulls looks to continue their season-long transformation from a fringe playoff team in the post-Michael Jordan era to an Eastern Conference power. Deng has become a man at ease, completely comfortable with his role with the top-seeded Bulls.

"You can't say enough about what he does for our team each and every night," said coach first-year coach Tom Thibodeau last week. "You can't measure it statistically."

MVP favorite Derrick Rose has received all the fanfare this season, and deservedly so. But Deng's contributions on both ends can't be overlooked, and his importance to this team was made even clearer Saturday, Deng's 26th birthday, as Chicago rallied for a 104-99 Game 1 victory over the Pacers. Deng struggled to find a rhythm in the first half, going 1-for-4 from the field and 0-for-2 from the line while the trailing Bulls allowed the Pacers to shoot 62.5 percent from deep.

Deng shot 6-of-8 in the second half while nailing a three with 5:24 left in the fourth to give Chicago its first lead of the game. He finished with 18 points and 10 rebounds.

Just nine months ago, Deng was scrutinized for not living up to the six-year, $71 million contract extension he signed in 2008. He was tossed around freely in trade rumors, linked to deals involving Andre Iguodala and Carmelo Anthony. He was largely written off, labeled as another gifted athlete who never reached his full potential.

And on paper, Deng's year-to-year numbers appear to abet that claim. He's seemingly the same player as last season. But he's been invaluable on both ends of the floor and some offseason adjustments have paid major dividends in the Bulls' breakout campaign. In short, Deng has proved just why Rose lobbied so hard to keep him at small forward when Chicago's front office was among the many LeBron James suitors last summer.

The most obvious change this year was his three-point shooting. Entering the 2010-11 season, Deng was a career 31 percent three-point shooter, netting 101-of-327 attempts. He was 115-for-333 this year alone, ranking just behind Kyle Korver for the second most attempted threes on Chicago's roster. At Thibodeau's urging, Deng has developed into a legitimate perimeter threat.

"Coach told me from the start of the year he wanted me shooting those," said Deng. "I'm comfortable shooting them now."

His expanded range does some key things for the Bulls. When they set up in a 1-4 offensive set (Rose at the point, Deng and Korver on the wings, Boozer and Joakim Noah down low), it forces opposing defenses to extend, creating space in the middle of the lane. Deng can then drive, dish or, as he did in the Feb. 24 matchup against Miami, showcase his revamped stroke.

When the Bulls rotate their shooters around the arc, it prevents opponents from collapsing, providing Rose with room to penetrate, and Boozer and Noah to operate in the paint. That's been strikingly effective: The Bulls offensive efficiency rating jumped from 28th to 12th this season.

Deng has also been remarkably durable. Hampered by wrist, knee and ankle injuries in previous seasons, Deng logged an absurd 3,213 minutes this year, third most in the NBA. He was one of only two Chicago players to start all 82 games (Keith Bogans was the other), and he led the team with a plus-6.4 average per game, tying Dwight Howard and pacing Kobe Bryant and Rose at No. 8 in the league. Even more impressive: Deng's health has compensated for injuries to Boozer and Noah. In the 50 games one or both were absent from the frontcourt in the regular season, Deng's averages spiked to 18.2 points and 6.2 boards.

"He's been the most consistent player for us all year," Rose said of Deng, who's been dubbed the leader of Chicago's bench mob. "Blocking shots, rebounding -- he stepped it up a lot."

But it's the other side of Deng's game that's been his calling card: His length -- he has a 7-foot wingspan -- has anchored the league's stingiest defense, holding opponents to a 91.3 points on 43 percent shooting this season. His coverage late in games has been even stiffer, propelling the Bulls to surrender a league-low average of 21.5 fourth-quarter points.

"It would be a shame if he got overlooked [for the All-NBA defensive team]," said Thibodeau. "By far he's our best individual and team defender."

Everyone knows Rose is the team's go-to offensive option in the clutch. He takes the crucial shots, the celebrated game-winners he's connected on so many times. What most fans don't realize is Deng is that go-to presence on defense, routinely asked to lock down the other team's premier scorer. In the postseason, that could be LeBron James, Paul Pierce or, in a best-case Finals scenario, Bryant or Kevin Durant.

It's easy to forget, but Deng is the longest-tenured Bull. He's been there since 2004, the poster child for the team's growing pains. He suffered through 49 losses in 2007 and 41 in both 2008 and 2009. He paid his dues, patiently waited to compete for a team that could be considered of championship caliber.

Now that the time's here, he's unmistakably calm. And his impact is not lost on teammates.

"He's been great all season," said Boozer.

"I don't think we would be in the position we are right now if it wasn't for Lu," said Noah.

"When other guys don't have it going you can always depend on Lu," said Bogans. "He does all the little things plus he can score the ball."

He's Chicago's glue guy. Deng has quietly held the team together, facilitated the Bulls relentless run through the East. The local media have even awarded him a new nickname. "Glue-All" Deng. He's gone from criticized to beloved.

That's why Rose staunchly defended him during trade talks. That's why GM John Paxson firmly stood behind his once controversial contract extension. Without his leadership, the Bulls likely wouldn't be rolling into the playoffs as favorites rather than underdogs. He's become irreplaceable.

"The guy never quits," said Thibodeau. "We need that."

Following the Bulls 97-81 takedown of Boston on April 7 -- a game they controlled from the outset -- Deng again hovered in front of his locker, savoring the triumph. He was brilliant, notching 23 points, six rebounds and two emphatic blocks. As reporters circled him, constantly shuffling for position, he remained composed. He was unfazed.

Asked if the victory was a precursor to the postseason, a symbolic passing of the torch from the Celtics' aging core to Chicago's blossoming youth, he simply shrugged, another reminder of his perpetually cool demeanor.

"When the playoffs start everything is over with," he said. "We don't fear no one, but we respect what they've done and what they're capable of doing."

That's the thing about this Chicago bunch. They have perspective. They may lack Miami's star-power or Boston's Hall-of-Fame roster, but they haven't needed them to beat those teams this year. They may not need them in the playoffs either. Unlike the others, the Bulls most closely resemble a complete team.

Rose is the unquestioned hero. Boozer the strong silent type. Noah the eccentric energy guy. Deng is their perfect complement, a levelheaded, highly intelligent player who brings out the best in each of them. It's his maturation that has made the team thrive.

True to form, he's the last to admit it.

"I feel like every guy in this locker room is just as important," he said. "It's not about me. It's about the team."

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