After taking batting practice, Puig played catch Thursday under the watch of trainer Stan Conte.
"We don't think it's serious, but we need to find out," Mattingly said, calling Puig's reduced throwing "precautionary."
The 23-year-old Puig was runner-up in National League Rookie of the Year voting last year, bursting on the scene by hitting .319 with 19 homers and 42 RBIs in 104 games, although he tailed off significantly after a record-breaking first month of June.
Puig had trouble adjusting to better pitching and struggled with fundamentals, such as hitting the cutoff man with throws and knowing when to take the extra base on offense.
Mattingly repeated earlier comments that he doesn't want to take away Puig's aggressive nature or enthusiasm for the game, but is looking for improvement nonetheless.
"His main challenge will be scouting reports," he said. "Once the competition starts and he shows spots he can't hit, shows tendencies, that's the adjustments you see from the baseball side. What they [pitchers] try to do and what adjustments he makes. It's a constant game of adjustments, of cat and mice.
"Last spring, it was hard not to like what you saw -- he hit .500 or .600. Over time, you see areas you're concerned about, certain fundamental things. But I won't modify the way he plays. It's hard to see a team get upset when a guy gets excited. Every team does it. They can't get mad when they do the same things. We just want him to play the game right."
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.