Japanese pitcher Masahiro Tanaka was released from the hospital on Sunday after being felled by a hard line drive up the middle during a training session at Yankee Stadium on Saturday.
He was treated and released the same day.
"Masa had concussion-like symptoms that have since dissipated. He went through a battery of tests at the hospital; everything checked out well," Yankees manager Aaron Boone said.
Boone added that Tanaka has been placed in "concussion protocol" for follow up treatment.
The incident happened on the Major League Baseball team's first official day of workouts ahead of the start of the delayed American baseball season.
The 31-year-old Tanaka said on social media he was looking forward to getting back on the mound.
"I appreciate all the support. I feel it a bit right now, but I'm all good. Going to try to get back on the mound ASAP! Thanks again for all the encouraging words!"
In six seasons with the Yankees, Tanaka is 75-43 with a 3.75 ERA, 947 strikeouts and 200 walks. Tanaka posted an 11-9 record with a 4.45 ERA in 32 appearances last season.
The Yankees have already lost one starting pitcher to injury, with Luis Severino undergoing Tommy John surgery a couple of months ago.