His fine for the incident was also reduced to $1,000, the source said.
With two outs in the first inning, Musgrove grazed Donaldson's jersey with a pitch. As Donaldson headed to first base, he exchanged words with Musgrove and took a few steps toward the mound before Diaz intervened. Donaldson shoved Diaz, prompting players from both dugouts and bullpens to spill onto the field. No punches were thrown and the field was quickly cleared.
Donaldson and Musgrove were ejected from the game, and Pirates manager Clint Hurdle was ejected by plate umpire Brian Gorman for arguing the decision to toss Musgrove.