BOSTON -- Hank Blalock may not be coming off the disabled list as soon as he anticipated, but the Rangers are hoping he'll be able to return to the lineup on Monday against the Tigers.

First he'll have to make a two or three day stop in Double-A Frisco on medical rehabilitation assignment and show the Rangers that he's ready to play third base again. He was hoping to avoid a rehab assignment and be activated while the team is in Boston.

"I respect the fact that they want me to do that because of the way the season has gone," Blalock said. "I was looking forward to playing here [in Boston] but I'll go out and play hard on rehab and be ready to help my team."

Blalock is sidelined with inflammation in his right shoulder. Earlier this season he missed more than 2 1/2 months because of a torn left hamstring muscle and right wrist surgery, then developed the shoulder inflammation in just a week after being activated off the disabled list at the All-Star break.

The Rangers had been planning to move Blalock to first base, but now are determined to leave him at third because of the presence of Chris Davis. They also want to make sure the shoulder is strong enough to play the position.

"My feeling is we need to see Hank play third base for three days," manager Ron Washington said. "Make all the plays, do all the work and don't have any setbacks."

Blalock went through a rigorous workout on Tuesday at Fenway Park, throwing from third to first, and to second base on the around-the-horn double play. The shoulder held up under those controlled conditions. He also started taking batting practice.

"My arm feels good," Blalock said. "I went through their throwing program, now I want to finish the year playing third every day and feeling strong. That's my goal."