Tony Kemp, who like Rasmus is a left-handed hitter, came off the bench in a key pinch-hit spot in Tuesday's win over the A's. Hinch told reporters after the game Rasmus wasn't available.
"I hadn't been feeling like myself out there on the field, and I just felt that it may be better for somebody else to get in there," Rasmus said Wednesday. "Kempy got in there and did something cool. Just taking a little breather."
When asked exactly what was keeping him off the field, Rasmus said he wasn't himself.
"Just don't feel that I can get out there and do as good a job as somebody else," he said. "I don't think it's fair for them or fair for the team to get out there if I'm not feeling I can get the job done."
Hinch said he could tell Rasmus was struggling in Seattle and talked to him prior to Monday's series opener against Oakland, where it was determined he wouldn't play.
"It's sad to watch him try to grind it out when he's not feeling great," Hinch said.
It's been a rough second year in Houston for Rasmus, who was a postseason hero last year for the Astros. After accepting a $15.8 million qualifying offer in November, he's hitting .206 with 15 homers and 54 RBIs, though he's been a non-factor in the second half.
"I think it's a little bit of everything," Hinch said. "I think his body has failed him a little bit. If it's not one thing it's another. Physically for him, he takes a big toll on his body to play this game. Obviously, he's played a number of years and it's taken a little bit out of him. He knows his body very well, he knows what he can and can't do, and I have to make a judgment whether to put a guy in when he's less than 100 percent."
Rasmus admitted he's struggled at the plate during at-bats and said not having the kind of season he wanted to have has weighed on him.
"The game can beat you into submission at times, you know?" he said. "It's worked on me a little bit so I'm just trying to get my right to try to finish strong."
Brian McTaggart has covered the Astros since 2004, and for MLB.com since 2009. Follow @brianmctaggart on Twitter and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.