SAN DIEGO (AP) — Padres star shortstop Fernando Tatis Jr. hurt himself taking a hard swing Monday night and immediately left the game against the San Francisco Giants.

Tatis struck out swinging against Anthony DeSclafani and winced in pain as he fell to the ground. He cradled his left arm while he got up, and two trainers helped hold his left arm against his body as he was helped off the field.

The Padres said Tatis has a “left shoulder subluxation,” also known as a partial dislocation.

“He will be re-evaluated tomorrow,” the club said in a tweet.

The 22-year-old Tatis left a game late in spring training with left shoulder discomfort but was back two days later. Manager Jayce Tingler said then that Tatis had been dealing with left shoulder discomfort since his minor league days. Tatis later said he’d had it since rookie ball.

Tatis has struggled this season, committing five errors and hitting just .167, although he hit a 465-foot home run in Sunday’s loss to Arizona.

He signed the longest contract in big league history on Feb. 22, a 14-year, $340 million deal.