Steve Nash has lingering back issue he believes will go away soon

DALLAS — The defining legacy surrounding Steve Nash goes beyond his superb passing.

It also involves how he’s managed his longevity in his 17-year career despite lingering back issues. But Nash said the back spasms he endured in recent days appears to be a unique albeit temporary issue where his muscles have tightened.

“I don’t know if I made some sort of movement or if I got hit or something,” Nash said following the Lakers’ 103-99 victory Sunday over the Dallas Mavericks. “I had my veterebrae lock up on me and the muscles overcompensated and it created spasms. I don’t have much freedom.”

Nash said he originally felt those muscles tighten up in the first quarter of the Lakers’ win Friday over Portland. But with minimal time for treatment, Nash attributed those back issues as the main cause for his 2 of 11 mark from the field against the Trail Blazers. Since then, Nash received more treatment from Lakers physical therapist Judy Seto. But the Lakers guard hardly pointed to his 20-point performance on 7 of 12 shooting against Dallas as signs that his back improved.

“It’s a funny thing. I struggled [against Portland] and I thought some of the the balls would go in and they didn’t, Nash said. [Against Dallas], some of them I was willing them in. They didn’t feel good. Towartd the end of the game, they felt better. At this stage, you can’t think about it and just play and help your team. If you’re not much help, it’s up to the coach to decide. I was going to do what I can.”

Though Kobe Bryant headlined the effort with 38 points on 13 of 21 shooting, Nash’s improved shooting still played a huge part in the win. Bryant set Nash up for a 3-pointer that gave the Lakers a 99-95 lead with 2:13 remaining.

“There were stretches tonight where I didn’t feel that great,” Nash said. “I just tried to play as hard as I can and figure it out as I went along and try not to think about it.”

Nash will likely have to adopt that same mindset when the Lakers (28-29) play tonight against the Denver Nuggets (35-22). The Lakers’ schedule opens up after that. They won’t play until Thursday when they host the Minnesota Timberwolves at Staples Center. They’ll then have a game Sunday against the Atlanta Hawks.

“The problem is I have to play,” Nash said. “If it was a few days, Id think it’d go away easily.”

Follow L.A. Daily News Lakers beat writer Mark Medina on Twitter. E-mail him at mark.medina@dailynews.com