Boone said Tanaka showed concussion-like symptoms at the ballpark but they dissipated at the hospital. Tanaka was released from the hospital Saturday night and will enter concussion protocol.
"I appreciate all the support", Tanaka wrote on Twitter.
At about 3:30 p.m., the 31-year-old Tanaka fell to the ground and stayed there for several minutes.
"Anytime you see that on a baseball field - and then add in there that it's a teammate - that stops you in your tracks", Yankees manager Aaron Boone said according to MLB.com.
2 dead, 8 wounded in USA nightclub shooting
According to the Greenville County Sheriff's Office, no one is now in custody and police are actively investigating the shooting . A deputy with the Greenville County Sheriff's Office noticed a disturbance at the club, Lavish Lounge, shortly before 2am.
The simulated game was broadcast live on the YES Network, and Yankees fans tweeted prayers for Tanaka after the clip quickly went viral.
I realize I am sort of out of bounds here because we are technically social media too, but the posts and video about Tanaka going down were tough to watch, over and over again. The opener carried a somber feel after Stanton's comebacker drilled Tanaka in the right side of his head in the third at-bat of the session.
Pitcher Jordan Montgomery began warming up and started to throw to hitters about five minutes after Tanaka walked off.
Yankees players stood by silently as the medical staff rushed over to attend to the starter, who is a key piece of the team's rotation. "I requested it after that, just because I was little shaken up".
Some Yankees pitchers got another scare during batting practice, when a line drive rocketed into a pack of players gathered along the left field line.