His rant led to backlash from horse racing fans on X, formally known as Twitter, and Kelce first doubled down on his theory, explaining why he believed the horse was on steroids during competition. “I’ll admit I don’t know whether Secretariat was on steroids or not, it’s impossible to know, because in 1973 when Secretariat won the triple crown there was not adequate testing available to find out,” he wrote.

“But, the fact this horse had unparalleled muscular stature and died with an enlarged heart, and raced at a time when steroids were extremely prevalent, without adequate testing, raises flags in my book…I’m not saying what Secretariat did was unimpressive, because he was likely also racing against other majorly juiced up horses of his time, and if Secretariat was indeed a natural horse, that would make his accomplishments all the more impressive,” the post read.

“I just find it highly unlikely given the circumstances of where the sport was at that time, how dominant the horse was in the era, and the records it still holds to this day,” the post continued.

Jason Kelce.

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Kelce closed out the post, adding “The horse was undoubtedly born with incredible natural mechanics and ability, and may have been natural, but I also think that it’s unlikely given the time it raced and what was happening with a lot of those horses and the lack of testing available.”

Kelce added that despite his belief that Secretariat was on steroids, he doesn’t discount the horse’s records, much like he still feels that Barry Bonds is the best slugger to ever play in the MLB.

“I agree, that’s why I said the horses accomplishments are still Valid,” he said, replying to a user on X. “We all know Bonds Juiced, he’s still the greatest hitter of all time in my opinion. He also did it against a large amount of players who were also juiced.”

But as the backlash continued, Kelce issued an apology.

“I’m sorry everyone, wasn’t trying to get people riled up, I really thought it was just known that in the 70s steroid use was rampant.  I’m not trying to take away from Secretariat’s, or anyone from that era’s legacy.  You’re right, without proof it is unfair to assume these things publicly, I apologize,” he wrote on X.

Secretariat’s times set at the 1973 Kentucky Derby, Preakness Stakes and Belmont Stakes are still the fastest on record, 51 years later.