ARLINGTON -- The Rangers are hopeful they'll be getting a healthy Josh Hamilton back for the second half.

The outfielder is scheduled to undergo surgery on Tuesday to repair a partially torn abdominal muscle and is expected to be sidelined for four to six weeks. The Rangers are hoping he can return after the All-Star break.

The Rangers could have used his bat on Monday night, as they lost to the Blue Jays, 6-3, in the opener of a home series.

The surgery will be done in Philadelphia by Dr. William Meyer, who examined Hamilton on Monday and confirmed the original diagnosis of a partial tear. The injury is not considered as serious as the sports hernia that sidelined second baseman Ian Kinsler for the final six weeks of the 2008 season.

"Given what it could have been, this is better than some of the alternatives," Rangers general manager Jon Daniels said.

Hamilton, who missed two weeks at the start of May because of a bruised left ribcage, injured himself crashing into the wall while making a spectacular catch against the Angels on May 17. He hit .237 with one home run and five RBI in 11 games while trying to play through the pain before finally being put on the disabled list on Tuesday in Boston.

The Rangers open the second half at home on July 17 against the Twins.

"It's great in that we thought it might be longer," Rangers manager Ron Washington said. "We thought [Hamilton] might be out until September. Now we have a chance to get him back after the All-Star break. At least it won't be until September. At least we know what we're dealing with and we have a time frame."

With Hamilton out, Washington said Marlon Byrd will be his regular center fielder. He said there might be a chance that Andruw Jones could play out there as well. The Rangers are not expected to look outside the organization for outfield help, although they have talked to David Dellucci about a Triple-A contract.

"You can't go out there and replace what Josh brings us," Daniels said. "It's not a possibility. The reality is we haven't had 100 percent of Josh all year. This team has proved that they can win with the guys we have here. We're going to continue to stay with this group."

The injury ensures that Hamilton will be not be returning to the All-Star Game after last year's star turn in the Home Run Derby. He has been second in fan voting among American League outfielders in each of the past two updates and also expressed a desire to compete in the Derby again. But his injury will keep him out of the All-Star festivities all together.

Instead, the Rangers want Hamilton back to the All-Star level he played at in 2008, when he led the AL with 130 RBIs. He also hit .304 with 98 runs scored and 32 home runs. He has played in just 35 games this season and is hitting .240 with six home runs and 24 RBIs.

"Obviously, Josh is a massive part of our club," third baseman Michael Young said. "The bad news is he'll be out that long, good news is he'll be able to come back healthy and ready to go. Whenever you have an injury that requires surgery, the best hope is to make sure you get it taken care of as soon as possible."