ARLINGTON -- Rangers center fielder Josh Hamilton left Friday's 5-1 loss against the Twins in the fifth inning with lower back spasms and is day to day.

"It's weird, man. I don't know how to describe it because I've never felt anything like it before," Hamilton said. "It was hurting all the way in my hips. My legs were weak."

Hamilton hurt his back while tracking a fly ball off the bat of Brian Dozier in the top of the fifth inning. He couldn't come up with it as he made his fifth error of the season, and Dozier reached third base on the play. In the bottom of the fifth, Leonys Martin pinch-hit for Hamilton.

"I honestly wanted to walk in from left field," Hamilton said. "I felt it grab me just as I got closer and closer to the wall. It's no excuse for not catching it, of course. It was just something like I had never felt before."

Hamilton's status for Saturday's game against the Twins is unknown, although he said he was feeling better after Friday's loss, the Rangers' fifth in a row. He was also confident that the injury would not jeopardize his chances to play in the All-Star Game on Tuesday at 6:30 p.m. CT on FOX, when he is set to start in left field for Ron Washington's American League squad at Kauffman Stadium in Kansas City.

"He has lower back spasms, so we'll go day to day with him," Washington said.

"I'll know when I wake up tomorrow morning," Hamilton said. "It still hurts. It's not as bad. After I iced it, it actually felt worse, but then it thaws out and it feels better. It's a good sign."

Hamilton, whose 74 RBIs and .641 slugging percentage lead the Major Leagues, was 0-for-2 before exiting the game. Since returning after being hospitalized with an intestinal virus in June, Hamilton has played in 17 straight games, starting the last 16.