Dodgers outfielder Yasiel Puig is already on a limited throwing program after a flareup of inflammation in his right shoulder that bothered him sporadically last year.

Manager Don Mattingly said Puig apparently overthrew his first day in camp and the club believes it is the same problem that he played through last year. Position players have been working out voluntarily this week leading up to Friday's first full-squad workout.

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.