New York Yankees right-hander Masahiro Tanaka was back at Yankee Stadium on Sunday, a day after getting hit in the head by a line drive off the bat of Giancarlo Stanton.Tanaka’s quick return — and relatively minor injuries — is even more amazing when considering the speed at which that line drive was traveling when it hit Tanaka.”That ball came back, I think they said 112 mph,” Yankees lefty James Paxton told reporters Sunday.The official diagnosis for Tanaka is a mild concussion, manager Aaron Boone told reporters.”He came in around noon today and was in really good spirits,” Boone said of Tanaka. “Got a really good night sleep; no loss of appetite. We’re encouraged where he is and we’ll take it day by day, but hopefully it’s not something that’ll take too long. Since he got to the hospital, he’s pretty much been symptom free and feeling good … (and was) in good spirits popping around today, so I think at this point we’re really encouraged.”Tanaka, a two-time All-Star, posted an 11-9 record with a 4.45 ERA in 32 appearances (31 starts) last season with New York. The 31-year-old sports a 75-43 record with a 3.75 ERA in six seasons with the Yankees.