Scott was examined by team doctors, who diagnosed Scott with a hyperextended elbow. He'll be evaluated on a day-to-day basis. He will not play on Wednesday and will be re-examined prior to Friday's opener with the Cardinals.
He did pinch-hit in the ninth inning on Tuesday, but that's as far as he can go at this point.
"He can hit," Garner said. "He can't throw."
Scott sprained his elbow sliding into second base during Monday's loss to the Pirates. He had already reaggravated a prior injury in that area from a few diving catches during Spring Training, and his slide Monday just made everything worse.
Jason Lane received the start in right field on Tuesday in Scott's place, which prompted Garner to shuffle the lineup. Morgan Ensberg, originally slated to hit second, moved to fifth, with Lane hitting sixth. Chris Burke jumped from sixth to second.
Lane homered in his second at-bat as part of a 2-for-4 night.
"I'm disappointed that Luke can't play," Garner said prior to the game. "Luke needs to answer the bell often. But I'm not at all disappointed in playing Jason Lane. I had planned to play him [Wednesday] night. We'll do it one day sooner."
Opportunities: When Spring Training ended, Lane had a feeling he knew which way Garner was leaning in terms of picking an Opening Day right fielder, but he still held out hope that his spring performance had swayed the skipper to throw ample playing time his way.
No such luck. Garner met with Lane and told him Mark Loretta was his first option off the bench in pinch-hit situations, and that Scott would get the majority of the playing time in right field.
After starting at that position the two previous Opening Days, Lane was disappointed he would be on the bench this year.
"It's not a good feeling," he said. "To go out and have a good spring and lead the team in most offensive categories and not be one of the three outfielders is frustrating, but that's the way it is."
Assuming Scott's latest setback won't hinder him for long, Lane can expect to receive a handful of starts against lefties as well as serve as the occasional defensive replacement in right field. He could also start in center when Burke infrequently receives days off.
"Now I'll just work on staying in shape, conditioning and just making sure I'm ready to seize any opportunity I get," Lane said. "Make the best of it and hopefully change their minds."
Odds and ends: Monday's season opener attracted the largest television audience for an Astros game since 2004. The telecast on FSN Houston registered a 7.3 Nielsen household rating and a 12 share, the best since a 7.4 on Oct. 1, 2004, against the Colorado Rockies. An average of 145,000 homes in Houston watched Monday's game. ... The U.S. Army Golden Knights Parachute Team put on a pregame show on Tuesday, after having to cancel the performance on Opening Day due to inclement weather. Seven members of the team flew over Minute Maid Park and landed on the outfield grass. ... Brad Ausmus received his third Gold Glove Award during an on-field presentation prior to Tuesday's game.
Coming up: The Astros and Pirates will conclude their three-game season-opening set on Wednesday at Minute Maid Park, beginning at 7:05 p.m. CT. Right-hander Woody Williams will make his Astros debut, facing Bucs lefty Tom Gorzelanny.
Alyson Footer is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.