3 of the 4 Finalists last season have been struggling since.
Julio Rodriguez, Randy Arozarena, Luis Robert Jr.
Rodriguez after the home run derby last season: .308/.363/.578, 19 homers. Has had a tough year this year but I can't imagine it's because of a homer competition which didn't hamper him at all that season
Robert: got hurt in the second half, also has been hurt this year. Hit .251/.291/.498 after the derby. Still hit 12 homers before his season ended in September
Arozarena has always been overarozarated. Last season he was carried by a huge March/April where he hit 1/3rd of his homers and batted .330. He had a good bounceback August after slumping before the all star break.