Trump was threatening Kushner, but it had nothing to do with football players.

https://www.law.cornell.edu/wex/brady_rule

Effectively, Trump was threatening (blackmailing) him with "Brady Material"

A "Brady material" or evidence the prosecutor is required to disclose under this rule includes any evidence favorable to the accused--evidence that goes towards negating a defendant's guilt, that would reduce a defendant's potential sentence, or evidence going to the credibility of a witness.

How/when that would manifest is anyone's guess. Something tells me Kushner capitulated and now he's whining about it with his book deal (DeepState payoff) to A - besmirch Trump and B - try to get back in with the "club" by saying "he blackmailed me, I had to do what he said."

This is how the Political Game is played.