Zack Greinke had a priceless reaction to Xander Bogaerts' monster HR in ALCS Game 4

The Houston Astros gave the ball to 37-year-old Zack Greinke to start Game 4 tonight of the ALCS in Boston and hoped the veteran, whose last start came on Sept. 19, could slow the Red Sox's ridiculous offense down a little bit.

Well, it didn't take long for Boston to get to Greinke as Xander Bogaerts blasted a two-run bomb over the Green Monster – and completely out of Fenway Park - in the bottom of the first inning that gave Boston a 2-1 lead.

Bogaerts' blast was Boston's 21st home run of the postseason and it was an absolute no-doubter.

Check it out and look at Greinke's immediate reaction. He knew right away that it was gone.

Greinke was later pulled from the game with one out in the second inning.

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