The Rangers won, 2-1, to tie the series at 1.
Craig Gentry was in center field. Rangers manager Ron Washington said that's more about Gentry being comfortable in center than it is about giving Hamilton any kind of break in the field.
"I'm going to let pain be my guide," Hamilton said. "I've talked to the trainers and they've said, 'Trust that. Don't push it past that point.' Me, knowing there's just six games left, wants to push it past that point. But at the same time, I also want to finish the six games."
Hamilton said a day off or just pinch-hitting or being the designated hitter when the series shifts back to Arlington really wouldn't help him. It's just something he has to manage.
"It is what it is," Hamilton said. "It's hurting doing everything."
Hamilton said he was playing at about 75 to 80 percent, revising his previous statement of 50 percent that he indicated on ESPN 103.3 FM after Game 6 of the AL Championship Series.
"I'm comfortable playing at that level," Hamilton said.
Hamilton said the pain is at its worst when he checks swings and that it can hurt him for another 15 minutes or so even after that, impacting the rest of a particular at-bat.
"I don't want to check swing anymore," Hamilton said.
Hamilton, in fact, checked his swing when he batted in the first inning Thursday night. He then shattered his bat on a soft groundout, and slowly jogged to first base.
Hamilton said any kind of explosive activity makes it worse, such as running or check swings or even hard full swings.
"It's just gotten little bit worse, but this isn't something that's going to deter us from our goal or what we want to do," Hamilton said. "I'm not looking at it as a big deal."
Said Rangers president Nolan Ryan: "We've been aware of it. So far, it has been manageable. I'm optimistic that it will stay that way."
Despite the injury, Hamilton is hitting .267 this postseason with seven RBIs. He was 0-for-4 with a strikeout in Game 1. He hasn't hit a home run since Sept. 23 but isn't concerned about that.
Hamilton said the groin has bothered him for two months now.
"I was at a point when it first starting bothering me where I could warm up and it would feel fine," Hamilton said. "Then I got to a point where I couldn't warm up and make it feel better."
Washington said he'll continue to keep Hamilton in the lineup. The manager talks to Hamilton every day to see how he's feeling.
"We'll figure a way to get through it and we'll figure out a way to help him get through it," Washington said. "Even if Hamilton doesn't do anything, he makes a difference just with his presence in our lineup. I want his presence in it and it's in there tonight. Don't be surprised if he comes up big, because I certainly won't.
Richard Durrett covers the Rangers for ESPNDallas.com. Information from The Associated Press was used in this report.