Who is this Johnson kid?

Who is  this Johnson kid?

 The Arizona Diamondbacks acquired Chris Johnson on July 27 from the Houston Astros. At Houston, Johnson hit eight home runs and drove in 41 in 92 games. Since he put on a Diamondbacks uniform the man has gone crazy at the plate. In eight games with the Arizona  Diamondbacks,  Johnson has hit five home runs and has knocked in 15 runs.

He hit two yesterday in Pittsburgh -- one in the eighth inning and another in the ninth inning, as the Diamondbacks rolled over the Pirates, 10-4.