Orix Buffaloes outfielder Kenichi Marumo underwent emergency surgery after being struck in the head by a batted ball, the team announced Friday.
Marumo was hit during practice Thursday but continued to train. He later complained of dizziness before being diagnosed with acute epidural hematoma and having the operation in the evening.
The team said Marumo is responding but will remain hospitalized for a week to 10 days. It is not known whether he will be able to return during spring training.
The Pacific League season starts March 27.