Hamilton, who has a history of injuries, was hurt when he fell while chasing a fly ball during outfield drills.
"I just fell and landed on my shoulder and bruised my shoulder," Hamilton said. "We'll give it 12 to 24 hours and see how it goes."
The Rangers said that no further tests are planned on Hamilton's shoulder. He is icing it and is listed as day to day.
Wednesday was the first day of full-squad workouts for the Rangers.
Hamilton hit .268 with 10 home runs and 54 RBIs last season, when he was limited to 89 games because of injuries. He spent more than a month on the disabled list with an abdominal muscle tear early in the season and missed most of September with a pinched nerve in his back.
It was a letdown from his breakthrough performance in 2008, when he hit .304 with 32 homers and 130 RBIs.