Miami ? Ron Rothstein doesn’t know how to fix the Miami Heat’s problems.

“There’s no magic wands,” Rothstein said. “I haven’t found one. Been searching a long time.”

Too bad, because the Heat are in desperate need these days.

Rothstein, the Heat’s coach in their first three seasons, is back leading the team again, having been chosen Wednesday as the interim replacement for Pat Riley, who’s taking a medical leave of absence because of hip and knee problems.

And Rothstein’s job, just as it was in the Heat’s early days, will not be easy.

The team’s stars – Shaquille O’Neal, Dwyane Wade and now Riley – are injured. Forwards Antoine Walker and James Posey aren’t allowed to play because their body fat levels are 1 percent over team orders. Miami has dropped four straight games to fall a season-worst five games under .500, and those numbers could plummet further Friday when the Heat open a six-game western road trip in Phoenix.

“He’s been here before,” said O’Neal, who’s played in only four games because of a knee injury but could return this month. “He’s been a head coach in this league before. He knows this system, he’s part of the system, he understands the system and it’s just up to the guys to make him look good.”

Right now, that’s a tough task for the reeling NBA champions, who wouldn’t be in the playoffs if the season ended today.

“Nothing good to say right now,” Heat center Alonzo Mourning said.

Friday’s matchup is of two teams headed in opposite directions. Phoenix has the league’s second-best record behind Dallas, is 13-1 against the East and already handled the Heat – sans Shaq and Wade – with ease this season. And Wade might miss his fourth straight game Friday with a sprained wrist.

“Looking at that game and looking at the way they’re playing and looking at the way we’re playing … wow,” Rothstein said.

Rothstein has four decades as a basketball coach, 27 of them in the NBA, mostly as an assistant. He coached the defunct Miami Sol for their three WNBA seasons, then was an assistant with the Indiana Pacers for one year before returning to Miami as an assistant to Stan Van Gundy in 2004.

Excluding two fill-in appearances for Riley at the end of last year’s regular season, he coached his first NBA game in more than a decade Wednesday.

It didn’t go well.

The Los Angeles Clippers built a 29-point lead before winning 110-95, hours after Riley said he’ll undergo knee surgery today.

No, Rothstein’s first day back wasn’t fun.

“It could have been better,” Rothstein said.

Rothstein is a Riley disciple of sorts, so there figures to be some continuity. And the rest of the staff, especially Erik Spoelstra – whom Riley indicated could be his long-term successor, someday – will have a loud say in the team’s direction.

“I’m sure there’ll be some change. I don’t think there’ll be a lot of change, but who knows?” said Heat center Michael Doleac. “Same staff, same organization. I can’t expect there to be too much change at all.”

The only thing Doleac wants to see changed is the Heat’s mood.

“There’s been a negative funk over the whole team for a while,” Doleac said. “And I think the first thing we’ve got to do is just get positive again, start enjoying playing basketball and being around each other.

“We’re playing a game here and it doesn’t feel like that at times.”