He said he felt a blast of pain during a collision with Carl Crawford on a fly ball during the first game of Sunday's doubleheader with the Tigers.
"They're calling it a contusion," Lowrie said. "It's not structural or any tear or anything like that. I just have to work through that knot -- it's pretty tight."
Drew Sutton continued his trip around the diamond and made his third start of the season at shortstop. It was the sixth start in seven games for the utility infielder, who has also spent time at second and third.
Lowrie sat out Sunday's nightcap and manager Terry Francona said he teetered with the idea of using the shortstop Monday, but wanted to be cautious, especially since some players didn't arrive back to their homes until around 3 a.m. ET on Monday morning.
"Because we're not taking [batting practice] on the field and it's a late arrival, I said let's just hit in the cage and as the day progresses, if you feel good, maybe we'll pinch-hit you," Francona said, noting that Lowrie will likely be in the lineup on Tuesday. "And he probably could certainly play today. But the more I started talking to him, I thought, 'OK, we're going to use our heads here.'"
Lowrie took batting practice before Monday's game, hoping to stay active and work through the stiffness. He's played in 24 of the club's 27 games in the month of May, but said, aside from his shoulder, he's been fully healthy this season.
"My body feels great," he said. "I'll continue to do treatment tonight and tomorrow, and I'm confident [my shoulder will] continue to get better quickly. It's gotten better since last night."