ARLINGTON – Josh Hamilton will begin a rehab assignment tonight at Double-A Frisco, his latest step toward returning to the Rangers lineup this week.

Hamilton, who had surgery to repair a partially torn abdominal muscle 20 days ago, will bat leadoff as Frisco's designated hitter when it hosts Corpus Christi.

Hamilton will be re-evaluated by the Rangers on Tuesday. If there are no complications, he will then join Triple-A Oklahoma City because Frisco will be off for its All-Star break.

The RedHawks begin a three-game series in Iowa on Wednesday night. General manager Jon Daniels said Hamilton could be ready to play for the Rangers on Saturday when they host Tampa Bay.

"That would be the earliest," Daniels said. "It's possible sometime during the series. The road trip [which begins July 6] is probably a little more likely."

Hamilton, who hasn't played since May 31, took batting practice, ran the bases and worked on his sliding Sunday.

■ Cruz sits again: Outfielder Nelson Cruz expected to be in the lineup Sunday after getting Saturday off. Manager Ron Washington had other plans.

"I wanted to give him a couple of days to get some work in, and he'll be back in there [Monday]," Washington said. "He's been grinding, and I felt like a couple of days would do him some good. When we got back here after that long road trip, he looked a little fatigued."

Sunday's game was the third time Cruz has sat in the last week. He has one hit in his last 22 at-bats and is hitting .143 over his last 18 games. Still, Cruz wanted to be in the lineup.

"I'm kind of surprised," he said. "It's the first time I've had two days off this year."

■ Mathis finding his groove: Right-hander Doug Mathis has worked 8 1/3 scoreless innings since he was recalled from Oklahoma City on June 3. That includes 3 1/3 scoreless innings Saturday.

Mathis started one game earlier this year, allowing five runs in five innings. But now he has a specific role, and it's agreeing with him.

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Texas Rangers SS Elvis Andrus leaps over San Diego's Scott Hairston to turn a double play.

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"When I got brought up, they told me I was going to be a long guy to give them length out of the pen," Mathis said. "I was prepared to be in that role, and I'm ready when they call me. It's a little easier when you have a role and you know what you're doing."

■ More surgery for Nadel: Radio play-by-plan man Eric Nadel will have surgery on his right eye today. The surgery will "reinforce the attachment of the retina," according to Nadel, who also had a procedure earlier this month on the eye.

Nadel will miss today's game but said he will return on the current homestand. Scott Garner will work today's game.

Because of the surgery, Nadel will not be able to travel on the upcoming road trip. Steve Busby will take his place.

■ Briefly: The Rangers called up Sunday's starter, Tommy Hunter, and put Matt Harrison on the disabled list with left shoulder inflammation. The move is retroactive to June 24.