Turns out Twins center fielder Byron Buxton had a very good reason for leaving Tuesday’s American League wild-card game at Yankee Stadium after three innings. According to a person with direct knowledge, Buxton was diagnosed this week with a cracked rib after initially being removed due to what the Twins announced as “upper back tightness.” Buxton suffered the injury making yet another highlight catch, crashing into the outfield wall to rob Todd Frazier of extra bases in the second inning of an 8-4 loss to the New York Yankees. Buxton will be fine, the person said, once the rib heals. That should allow him to go through his normal offseason training program after a period of recovery. Buxton, who played a career-high 140 games during the regular season despite injuries to his groin and left hand, stayed in Tuesday’s game for another eight batters defensively. He also hustled down the line to beat out a routine double-play grounder to shortstop with one out in the third inning, which allowed the tying run to score. Buxton then stole second base but appeared to be in some discomfort after sliding in safely.