The Giants outfielder spoke candidly about the encounter with Pham after the Reds' 5-1 victory over his club ... saying the whole thing stemmed from Pham accusing him of cheating in the fantasy league they're in together (you can't make this stuff up).
Pederson said the dustup was the first time Pham ran into him ... and claims there was no argument between the two before the slap occurred.
Joc shares details of what happened in his fantasy football league that started his altercation with Tommy Pham today pic.twitter.com/d9NBTwPVoG
Giants skipper Gabe Kapler -- who announced Friday his decision to skip the national anthem moving forward due to the current state of the country -- refused to comment on the situation between Pham and Pederson.
Pham's suspension is retroactive ... meaning since he already missed Friday night's game after being scratched from the lineup, he only has to miss the next two games against the Giants.