Eight years ago, Brook and Robin Lopez were no-shows at an early-season practice for the Stanford men’s basketball team. Mild irritation among their coaches and teammates grew into something that resembled obvious concern as the hours passed and they failed to materialize.

Kevin Danna, a team manager, recalled that the Lopez brothers were notoriously absent-minded about checking their phones, so reaching them could be difficult. A staff member soon called their mother, who also had not heard from them. Alarmed, she drove to the campus from her home in Fresno, California.

What could have possibly happened to them? How could these twin 7-footers have simply vanished from campus? Eventually, it was discovered that they had joined a few friends on an impromptu road trip — to Disneyland, some 400 miles away.

“The amazing thing is that we had the next day off,” said Drew Shiller, a former teammate. “If they had just waited one more day, nobody would have ever known.”

As talented as they were enigmatic, as charming as they were exasperating, the Lopez brothers left Stanford after two seasons for the riches of the NBA. Now 27-year-old veterans, they are finally together again — in New York, where Brook is a top scorer for the Nets and Robin roams the paint for the Knicks after signing a four-year deal.

They are older now, more mature, but their joint presence will nevertheless add a little spice to the Nets-Knicks rivalry, for the two brothers are simply not your typical pro athletes.

For instance, when Brook suggested over the summer that he would invite his brother to live under his staircase, in accommodations similar to those enjoyed by the literary character Harry Potter, Robin sounded amused.

“A very Muggle response,” he said at the time, referring to characters from the book series who lack magical powers. “I think obviously he’s trying to hinder or suppress whatever mystical abilities I may have. He can’t understand them, and I don’t blame him for that.”

Basketball has never defined the Lopezes, who, for the record, are maintaining separate residences in the New York area, although, as Robin notes, “I like hanging out with my brother.’’

The two attend Comic Con and dress as superheroes. They spend free time developing live-animation scripts and television pilots. They are full-fledged members of what Robin Lopez, an accomplished illustrator, described as “geek culture.”

“I’m rereading that, actually,” he said of a 912-page biography of Walt Disney that he toted around in the preseason. “I wanted to go through a few biographies, because I know there are some differences in Disney ideology.”

If others view their outside interests as potential distractions or dismiss their goofy personas as some sort of shtick, friends and former teammates emphasize that, no, this is really them. They really do love comic books. They really do obsess over Disney. They are nothing if not authentic. “They’re all about that life,” Danna said.

At Stanford, where they helped lead the Cardinal deep into the NCAA tournament in 2008 before becoming first-round draft picks, the twins exercised their creative freedoms. They did not crave the spotlight as basketball stars. But they learned to balance the distinct parts of their lives, often to the amusement of those around them.

“I think their teammates had fun with them,” said Doug Oliver, a former assistant coach at Stanford. “I think they also made fun of them. They tolerated them. You could go down the list of adjectives.”

A lot of believe it or nots

The morning after traveling to Northwestern for a game in November 2007, Oliver got up early and left the team hotel around 7:30 a.m. in search of coffee. The players were still sleeping, or at least Oliver assumed that they were. And then he spotted a familiar figure standing outside a comic book store.

“Robin?” Oliver asked, startled to see one of his starters on a deserted block. “What are you doing up?”

“Oh, I’m waiting for it to open, Coach,” Lopez said. “I have to be the first one in.”

Lopez had done his research. The store was in possession of a rare collectible. Oliver observed that the store did not open for another half-hour.

“Yeah, I know,” Lopez said. “But I’m afraid someone else might buy it before I do.”

As was the case with most episodes involving the twins, Oliver chose to wait until after the game to debrief Trent Johnson, who was then the team’s head coach, on his early-morning encounter. A good number of their conversations started along the lines of, “You’re not going to believe this, but ...”

“It was definitely an interesting dynamic,” Shiller said. “The coaches at times struggled to manage Brook and Robin, and you absolutely had to manage them.”

Kenny Brown, another former teammate, drove a Saturn Vue, a compact SUV not designed for 7-footers. But that did not prevent the Lopez brothers from requesting rides, specifically to comic book stores. All knees and elbows, they would fold themselves into the back seat.

“They were like, ‘Let’s do this!’” said Brown, who recalled his maiden trip to one such shop. “I didn’t buy anything. But I watched them buy everything.”

Shiller, who often roomed with Robin on the road that season, said Robin was always drawing in a notebook. He even sketched characters on his sneakers.

“You could tell that, man, this guy, he’s just not totally focused on the game,” Shiller said, “and I don’t think that’s a bad thing.

“Certain guys kind of want to get away and decompress and think about other stuff. Robin would definitely do that, and I think it helped him.”

It was true of both brothers. Mitch Johnson, the team’s starting point guard, said he arrived at this conclusion before a game against Southern California. Stanford’s coaching staff wanted the players to be locked in about 45 minutes before the tip, regardless of the opponent. That meant no phones, no computers and no outside influences. As team captain, Johnson was responsible for policing his teammates.

So Johnson was annoyed, he said, when he entered the locker room about 15 minutes before the start of the game to find the Lopez brothers watching an episode of “The Simpsons” on a laptop and giggling with delight. Johnson asked them to shut down the computer.

Brook Lopez proceeded to obliterate USC, amassing 18 points, 11 rebounds and 12 blocks in a 65-50 victory. Johnson approached his coaches afterward.

“I just said, ‘Hey, you know, we might want to change some things with our pregame policy on what guys are allowed to do,’” he recalled. “If Brook and Robin want to watch ‘The Simpsons,’ I’m not going to say a word after that performance. If that’s what they need to do, then that’s what they need to do.”

Fizz and focus

Trent Johnson did not make allowances for the Lopez brothers, former players said, but he did learn to cope with some of their unconventional choices. Like most coaches, Johnson had dietary guidelines for his team. In particular, he did not want his players drinking soda, an edict that apparently ran counter to the Lopez ethos.

“Those guys, they just loved pop, man,” Mitch Johnson said. “They were pop drinkers.”

The twins took full advantage on a team trip to Italy, roaming the streets of Rome with two-liter bottles of Fanta.

“I think Trent got to the point where it was like, ‘Man, they’re still handling their business, so what can I do?’” Mitch Johnson said.

The Lopez brothers collected their capital in games and at practice, where their intensity was infectious. If they were easily distracted away from the court, their focus seldom flagged once it was time to get to work. Athletes often talk about having an internal switch.

“I think everyone changes once you get between the lines and start actually playing,” Robin Lopez said last week.

At training camp with the Knicks this month, Robin made an early impression on teammates with his habit of kicking various objects (basket stanchions, padded bleachers) whenever a play went awry. He exhibited much the same behavior at Stanford.

“He would get so mad if somebody scored on him,” Shiller said. “You almost didn’t want to score on him because you were afraid that he’d get in your face.”

Strangely, the Lopez brothers reserved most of their aggression for each other. If they happened to match up in the post, teammates knew to tread lightly.

“They’d try to dunk on each other every single time,” said Brown, their former teammate.

Yet each brother was fiercely protective of the other. Danna, the former team manager, recalled one practice when a couple of players were giving Brook a hard time during a shooting competition. After Robin was knocked out, he was still seething over the treatment of his brother. So when Brook sank a free throw to eliminate one of his antagonists, Robin piped up.

“Nice shot, Brook!” he barked from the other side of the gym.

Joan Friedman, a psychotherapist and author who has studied twins, said that many identical twins grow up with an extraordinary sense of safety and compatibility.

“So even when they’re brutally competitive, it’s almost like they know they can be that way with each other and it’s OK because they would never really hurt one another,” Friedman said. “But if someone else — some outsider — is injurious in some way, they’re immediately going to go to the other’s defense.”

It was clear to teammates that the Lopez brothers felt each other’s pain acutely. On that same eventful trip to Italy, the team was on a boat ride when Brook lost his hat.

“Brook was pretty bummed about it,” Brown said. “But Robin was really bummed about it, too. I mean, it was just a hat. And most people would be like, ‘Brook, get over it.’ But there was such a connection between them — a mutual understanding that I’m guessing you could only appreciate as a twin.”

Oliver, the former assistant coach, said the twins were much more productive when they were on the court together. On his own, each brother seemed to overcompensate for the other’s absence. But side by side, they made a cohesive whole: Brook as the offense-minded scorer and Robin as the defensive stopper.

The Stanford coaches often wondered how the Lopez brothers would handle playing for different teams in the NBA.

“They obviously figured that out,” Oliver said.