Bryce Harper was allegedly threatened by a Major League Baseball official over the summer … this according to a bombshell claim made by a big-time agent.

Here’s the deal … Allan Walsh — a superagent who reps National Hockey League players — made the allegations on his “Agent Provocateur” podcast which he hosts alongside podcaster Adam Wylde.

Walsh mentioned a widely reported incident over the summer … when baseball insiders claimed MLB Commisioner Rob Manfred came into the Philadelphia Phillies locker room and attempted to talk to the players about a salary cap.

The Associated Press — citing an anonymous source — alleged Harper cussed out Manfred … a claim Harper never denied.

Now, Walsh — who is NOT Harper’s agent — says he’s heard there’s more to the story … claiming Harper and several other players were speaking with Manfred and others after the incident when an MLB official angrily confronted Harper.

Walsh claims this official — one he doesn’t name, though he does say it’s not Commisioner Manfred — told Harper he shouldn’t ever speak like that to the commisioner in public again.

This person then allegedly said, “That’s how people end up in a ditch” — a pretty major threat against one of the sports biggest stars if legit.

Worth noting … Walsh wasn’t in the locker room — adding he’s heard this story from people who say they were there. He offers no other tangible evidence to back his claim.