Ryan Garcia told trainer Joe Goossen his rib was injured, hence why he sat out the referee's count and lost to Gervonta Davis.
Tank emerged victorious by seventh-round knockout in the battle of young American lightweight stars in Las Vegas.
The fight got off to a tentative start before action broke out in the second round.
Garcia hurled speedy combinations at Davis, forcing him to grab hold.
However, he then became reckless and was knocked down as he missed with a left hook and was hammered by Tank’s counter left.
Garcia was cautious and allowed Davis to take control after surviving this knockdown.
As they hit the halfway point, Garcia had success again by hitting Tank with a couple of hard rights.
It was all over one round later though as he was smashed by a body shot, took a knee and sat out the referee’s count.
Showtime's All Access Epilogue documentary has now been released and shown what was said in the ring after the fight.
Garcia's trainer Goossen asked his fighter about the body shot: "Did it hit that rib part at all Ryan?"
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"Yeah," Garcia replied.
Goosen then said: "I knew it."
To which Garcia explained: "I didn't wanna continue because of my rib."
According to reports, Garcia has since sacked Goossen after the 24-year-old accused someone in his camp of being a mole.
Speaking on Instagram after the fight, he wrote: "Actually sad I had a mole in my camp.
"Like WTF that’s crazy but thank god it’s brought to light now."
However, the 24-year-old was adamant the mole had nothing to do with the defeat and accepted he lost fair and square.
He continued: "Also didn’t mean that to come off as an excuse or anything.
"I lost, period. I’ll come back but I’m just shocked that part of my team crossed me, someone, close to me.
"But it’s a testimony that you must be aware of anyone."
It's unclear if this accusation is related to Goossen's reported dismissal, but either way, Garcia appears to be looking for a new coach.
And despite the somewhat disappointing end, the fight pulled in 1.2 million PPV buys in the US alone.
This is a truly incredible number, and Oscar De La Hoya believes Garcia was the reason because he was willing to take on Tank.
In a tweet, De La Hoya said: "Garcia is the new face of PPV, like it or not.
"Davis only did 200k PPV a few times without Ryan. With Ryan, one fight generates over one million PPV buys."
So Garcia might have lost, but he is a huge name and will surely be back soon once that rib is healed.
He has faced plenty of criticism for not fighting on, including from Carl Froch as he laid into Garcia.
“As far as I’m concerned,” Froch said on his YouTube channel, “if you stay down to a body shot and you haven’t got broken ribs, which he didn’t because he was walking around giving hugs and handshakes to people after, if you go down to a body shot, you’ve got to get off the canvas, stand up, take your licks and go out on your shield.
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“Don’t stay down to a body shot, if you do, you’ve quit.
“For me, Ryan Garcia quit, it’s not good enough, you’ve got to stay in there and climb off the canvas.
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