MIAMI -- Rangers outfielder Nelson Cruz, who has been on the disabled list since May 29 with a torn left hamstring, will spend the weekend in Nashville on a medical rehabilitation assignment with Triple-A Oklahoma City.

The Rangers cleared Cruz after a second straight heavy workout at Sun Life Stadium. Cruz once again reported no problems or pain with his hamstring.

"It was like [Tuesday], it was good," Cruz said.

Cruz will play the outfield on Friday, be used at designated hitter on Saturday and play the outfield again on Sunday. If all goes well, he could be activated on Tuesday when the Rangers open a three-game series against the Pirates at the Ballpark.

"We just want him to go out and see live pitching," manager Ron Washington said.

Cruz has played in just 32 of the Rangers' first 64 games. He's been on the disabled list twice because of hamstring injuries, but is still hitting .327 with 10 home runs and 34 RBIs. He has a .405 on-base percentage and a .729 slugging percentage.

Nippert, not Harrison, to start Thursday

MIAMI -- Right-hander Dustin Nippert will be on the mound for the Rangers, making his first start of the season in the finale against the Marlins on Thursday.

The Rangers decided on Nippert over left-hander Matt Harrison because the Marlins have a predominantly right-handed lineup. They faced right-hander Tommy Hunter on Wednesday, and the only left-handed hitter in their lineup was left fielder Chris Coghlan, who was batting leadoff.

"We feel like the right-hander has a better chance," manager Ron Washington said. "Nippert has a good breaking ball and changeup. He can equalize that."

This is one reason why Nippert is on the roster. One of his strengths is being able to start or relieve on a moment's notice.

"I don't know ... we'll find out," Nippert said. "It's the first time doing it this year. I don't have any expectations, I just want to keep the bullpen out of the game as long as I can."

Nippert is 2-3 with a 4.60 ERA in 22 relief appearances this year. Last year, he was 3-3 with a 4.65 ERA in 10 starts, and 2-0 with a 1.86 ERA as a reliever.

His longest outing this season is three innings and 47 pitches against the Blue Jays on May 14. He threw 37 pitches over two innings against the Rays on June 6, and has pitched just once since then. He threw 22 pitches over 1 1/3 innings against the Mariners last Thursday in Arlington. He has not pitched on the road trip.

"We'll let him go as long as he can," Washington said. "We know he's a guy who can give us 50-60 pitches. We'll let him go as long as we can. We're not looking for seven or eight innings."

This spot in the rotation will come up again on Wednesday against the Pirates. Washington said the Rangers will decide later if it will be Nippert again, Harrison or somebody from the Minors.

Rangers relievers beat the heat in Miami

MIAMI -- The temperature was 91 degrees at 3:30 p.m. ET on Wednesday at Sun Life Stadium. The heat index was 100 degrees.

So what were the Rangers' relievers doing running pass routes and throwing a football around in the outfield 3 1/2 hours before their game with the Marlins?

"That's our running," veteran reliever Darren Oliver said. "You play out there, you have to run out there. We'll have time to cool down. It's camaraderie ... togetherness."

So who is the best receiver out there?

"I'll tell you who the most improved player is -- Alexi Ogando," Oliver said. "He just figured it out."

And the best quarterback?

"Good question," Oliver said.

"Not me," said Frank Francisco.

"Frankie has the best NFL body ... to be a linebacker," Oliver said.

"I'll knock you down," Francisco said.

What about Oliver as the quarterback?

"Too old," Oliver said. "I'm slow. I can't run. I have slow feet. That's why I'm a pitcher."

Rangers ponder way to use Vlad vs. NL

MIAMI -- Vladimir Guerrero was out of the lineup on Wednesday, as manager Ron Washington stayed with his plan of not using him in the outfield two days in a row. The Rangers are in the middle of a nine-game, three-series stretch on the road against National League teams, and the designated hitter isn't being used.

Washington wants to use Guerrero twice in each three-game series, but he doesn't want him playing out there two games in row. So far that has not been a problem. The Rangers were off on Monday, so Guerrero played Tuesday, was off on Wednesday and returns to the outfield on Thursday.

The Rangers then open a three-game series with the Astros on Friday. Guerrero will have to play two games in a row if Washington wants to use him twice in that series. Washington will do that, he's just not sure how. The one good thing is the Rangers are off on Monday, so Guerrero will get extra rest no matter how he is used in Houston.

"He's going to get two of them," Washington said. "I just have to figure out how to run him out there back-to-back."

Guerrero went into Wednesday's game hitting .336 with 14 home runs, while sitting second in the American League with 54 RBIs.

"He plays with such reckless abandon. I don't want him running into a wall going after a ball," Washington said. "He's showed if the ball is hit to him, he can catch it. But I don't want him to slip or catch a cleat. I just want him to hit."

Worth noting

The Frisco Roughriders are sending five players to the Texas League All-Star Game. Catcher Taylor Teagarden is one of them. Pitcher Blake Beavan is another. Also going are infielders Matt Lawson and Renny Osuna, and outfielder Joey Butler. ... Alexi Ogando was the first Rangers pitcher to win in his Major League debut since Matt Harrison on July 8, 2008. Ogando is the first reliever to do so since Doug Mathis on May 12, 2008. ... Marlins pitcher Leo Nunez had gone 17 1/3 innings over 18 appearances without walking a batter until walking Julio Borbon with two outs in the ninth on Tuesday. It was Borbon's fourth walk in 192 plate appearances. ... Rangers pitchers have allowed three or less hits in two straight games. The last time that happened was when Ken Hill and Roger Pavlik pitched back-to-back one-hitters on May 3-4, 1996, against the Tigers in Detroit.