Dirk Nowitzki, as usual the last one out of the showers after a typically long postgame session in the trainer's room, overheard teammate Tyson Chandler talking to a couple of reporters about the trouble a sore hip is causing the big man.

"I told him now he knows what it's like to play with no jumping and no lateral movement," Nowitzki interrupted with self-deprecating sarcasm, speaking a lot of truth in jest.

"Welcome to my world. No lateral movement, no vertical, no nothing. He said, 'It's tough to play like that.' I said, 'I know. It ain't easy.'"

Nowitzki, the face of the Dallas Mavericks franchise for what seems like forever, was never exactly known for his explosiveness. His limited leaping ability and lack of quickness has made the big German the butt of many jokes during his 17-year career, and he's cracked plenty at his own expense, too. Dirk Nowitzki is playing 29.5 minutes a game, his lowest since his rookie season in 1998-99. Layne Murdoch Jr./NBAE/Getty Images

But there's nothing funny about Nowitzki's fight with Father Time right now. Not with the opponent whom Charles Barkley, while predicting a steep decline for Dirk a few years ago, promoted as undefeated, winning so many rounds recently against a surefire Hall of Famer determined to compete for another championship during the golden years of his career.

Nowitzki claims he feels relatively fine physically, considering he's three-quarters of the way through the regular-season grind at the ripe old age of 36, but it's hard to believe while watching him creak across the locker room after games.

Heck, there's plenty of reason for Dirk doubt to creep in while watching him on the hardwood, too. It's one thing to see him overwhelmed by an awesome athlete like Serge Ibaka, who had 21 points and 22 rebounds in Oklahoma City's win over the Mavs coming out of the All-Star break. It's another to see Nowitzki look helpless as a help defender when a fringe player like Jimmer freakin' Fredette drives for an easy layup.

And it's really hard for Mavs fans to see Nowitzki, the sweetest-shooting 7-footer ever to play the game and seventh-leading scorer in NBA history, appear so damn average offensively.

However, that's the harsh reality right now. Nowitzki's numbers during Dallas' 5-5 stretch since the All-Star break: 12.6 points per game on 40.3 percent shooting from the floor.

"There's obviously always going to be an adjustment for any guy who gets older," Mavs owner Mark Cuban said. "But the same shots he'd make when he wasn't guarded, he should be able to make those. It's just not falling for him. It happens. We've just got to get it over with."

Nowitzki readily acknowledges he's been far from his best for much of this season. But he doesn't believe there's any way he could be if he's going to peak in the playoffs.

"I've got to keep plugging, keep fighting," Nowitzki said. "I'm doing a lot of extra work right now to be the best player I can be once the playoffs come around, even if that means right now being in a little hole. But once the playoffs roll around, hopefully I'll feel great."

The games, for the most part, are still fun for Nowitzki. But it takes a lot of work from a lot of people to get him on the hardwood consistently after Nowitzki has logged nearly 50,000 minutes in his NBA life including playoffs.

Nowitzki, a doting father of a toddler daughter with a son on the way, probably spends more time with Mavs athletic trainer Casey Smith than he does with his own family. Hours of preventative maintenance -- from old-school ice to new-age heating contraptions that look like ski pants with tubes -- are part of their daily routine, in addition to treating the aches and pains that come from running the floor and banging with guys who grew up watching him play.

Fortunately, Nowitzki hasn't had to deal with any significant injuries this season -- and an arthroscopic surgery to clean up his right knee in October 2012 is remarkably the most notable thing on his medical chart after almost two decades in the NBA -- but a mysterious stomach ailment that bothered him for most of December sapped some of his strength and affected his conditioning.

Smith, Nowitzki and coach Rick Carlisle are constantly communicating about managing Nowitzki's minutes. They've trimmed them under 30 per game for the first time since he was a 20-year-old rookie who wasn't sure he could cut it in the NBA. Nowitzki has been a DNP-OLD four times this season, although he did play all five games in the first seven days after the All-Star break, a grueling stretch of schedule partially to blame for his production dip.

Cuban invested in the athletic performance technology company Catapult in part because he was determined to do everything in his power to extend Nowitzki's career as long as possible and help him remain productive into his twilight. Nowitzki has embraced the technological advances, wearing a small device that collects data on his movement during practice and a watch that monitors his sleep patterns.

Nowitzki kids that he isn't so happy about Cuban's decision to hire Jeremy Holsopple in the summer of 2013 as the Mavs' athletic performance director, a title that pretty much means strength coach of the future. The offseason workout program Holsopple created for Nowitzki included more running and weightlifting than he'd ever done before. Despite 17 seasons' worth of mileage on him, Dirk Nowitzki has "got a lot of good basketball left in him," says Mavs coach Rick Carlisle. AP Photo/Brandon Dill

"That was one of the worst summers I've had strength coach-wise," Nowitzki said. "I was running up hills. I was running up tracks. I was in the weight room four or five days a week. But I felt great there in November before I got my little stomach issue in December that put me back a while."

Nowitzki doesn't do as much extra shooting as he used to, except during longtime mentor Holger Geschwindner's thrice-a-season visits from Germany.

Weight work, particularly focused on the legs, remains a priority for Nowitzki during the regular season, even at the expense of sapping some energy for games. Flexibility training and intense, extended stretching sessions are also part of the program. The plan is that the payoff will come when he's strong for the playoffs.

Nowitzki constantly talks trash to teammates and staffers during his off-court workouts, finding that to be the best way to motivate himself. But this part of the job isn't a lot of fun.

"Sometimes you don't really feel like going to the weight room and getting a session in or even stretching," said Nowitzki, who has long adhered to a strict diet and sworn off alcohol during the season. "It's just sometimes annoying, but I know in the long run that it helps me, especially if I want to play out this contract at a decent level for the next three years."

Nowitzki intends to play out the three-year, $25 million hometown-discount deal he signed last summer and then make a decision about whether to continue his career. His health will be a huge factor in that decision.

It's hard to tell how much Mavs president of basketball operations Donnie Nelson is joking when he says he thinks Nowitzki can be a quality contributor until he's 45. There's no doubt, though, that the Dallas front office and coaches are confident the basketball version of a BMW isn't about to break down.

"There's never been a 7-foot guy in the history of this league who's played his position the way he's played it to his age," Carlisle said. "And he's got a lot of good basketball left in him."

That's the hope, but Nowitzki knows all too well it won't be easy. Nothing is at his age in the NBA.