"He looked good," Harrison told reporters. "He's working his tail off in every aspect out here."
Less than halfway through a five-year, $125 million contract, Hamilton was traded to the Rangers by the Angels on Monday after two troubled seasons filled with poor performance, injuries, and an alcohol and drug relapse.
Hamilton, who is on the 15-day disabled list while recovering from right-shoulder surgery Feb. 4, is working out in Arizona before beginning an injury rehabilitation assignment with Triple-A Round Rock.
He is on track to be activated during the second half of May.
Information from The Associated Press was used in this report.