"It may not have been caused by the crash. He'd had aches and pains in the past, but it definitely irritated it," Falsone said. "Every time he swings, it irritates it."
She said surgery is not being discussed at this time, even if it's a logical option should the irritation continue.
Kemp expressed frustration with his latest injury, having earlier missed 51 games with a strained left hamstring.
"It's [injuries] been part of my game the whole year," he said. "I'm not saying I've gotten used to it, but I've had to deal with it. I want to be in the lineup. Most of the time I find a way to play and still be successful. I told myself with 20-something games to go to just push through. But right now, the way my shoulder feels, I wouldn't do much."
Kemp said he was dismayed when a ball he thought he nailed earlier in the week against San Diego was caught at the top of the fence by Cameron Maybin.
"He did a Spider-Man and most times I drive that ball far out of the park, but I didn't have that extra umph," Kemp said. "I finish [the swing] high and it hurts when I get up there."
Manager Don Mattingly said if Kemp's injury occurred at another point in the season, he'd probably be put on the disabled list.
Trying to play through the pain, Kemp is 3-for-29 since missing only two games after the collision, and he went 0-for-5 in Friday night's 5-2 loss to San Francisco, 0-for-4 with runners in scoring position.
He said he required sedation for the MRI, in which gadolinium dye is injected to enhance irregularities in the injured tissue.
"It was pretty overwhelming," he said of being inside the MRI tube. "I'd never been inside one, head-first. It was pretty intense. Pretty scary. They asked if I was OK. No. They gave me a little medicine. I'm still relaxed now. Most of the time I'm loud, a little obnoxious. I'm cool. It's nice."
Juan Rivera was in the starting lineup in left field Saturday, with Shane Victorino moving from left field to center. Rivera had a key double that led to the tying run.
"It's tough any time you lose Matt," said Mattingly. "We talked after [Friday night's] game. I appreciate that he wants to play and be tough, but at some point you're not helping the team. It doesn't do us any good if he's not able to compete and be productive. I hope he just needs a few days off and it's something he can manage."