Braves pinch hitter Willians Astudillo hit Miller's first pitch right back at Miller, who reached up as the ball hit him and bounced away for a hit. The pitcher threw his glove and walked into the Yankees' dugout.
Manager Joe Girardi said Miller suffered ''a substantial bruise.''
X-rays came back negative. Miller will also undergo a CT scan.
Dellin Betances came in from the bullpen to pitch for the Yankees after Miller left. New York won 2-0.