At the age of 16, Bryce Harper was on the cover of Sports Illustrated. Earlier this year, the now 18-year-old was discussed as arguably the best baseball prospect ever.

Latley, it seems the adulation is getting to the Washington Nationals' minor leaguer's head.

After hitting a home run in a Class A game between Hagerstown and Greensboro, Harper - who appears to be sporting a porn 'stache - blew a kiss to Greensboro pitcher Zachary Neal as he rounded third base.

In retaliation for his insulting display, Greensboro brushed Harper back during his next at-back.

Check out the video that has the baseball world buzzing.