Jordan Mason reveals 49ers may have broken NFL rule with Christian McCaffrey missing Week 1 game

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The San Francisco 49ers revealed in shocking fashion that star running back Christian McCaffrey would not be playing in the team’s opening game against the New York Jets on Monday night. 

However, what was shocking to everyone else did not seem so to his backup, Jordan Mason, who might have revealed the team broke an NFL rule following its 32-19 win on "Monday Night Football."

Mason, who had a career night in his first-ever start for the 49ers, was talking to ESPN’s Lisa Salters after totaling 147 rushing yards with a touchdown on 28 carries in the win when he said that he knew on Friday he was going to start over the injured McCaffrey. 

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San Francisco 49ers running back Jordan Mason reacts after a run against New York Jets safety Chuck Clark during the fourth quarter at Levi's Stadium. (Darren Yamashita-Imagn Images)

"When did I find out? Maybe Friday. Friday night, something like that," Mason responded when Salters asked when he found out he was starting. 

Mason had a postgame interview as well, when he appeared frustrated with another reporter asking again when he found out he was starting. 

"That question right there is why I’m mad," he said. "That’s why I don’t like really talking to media because you say one thing right and then, you know, I don’t know. Just skip that question."  

Head coach Kyle Shanahan said after the game that Mason did not know he was starting, but rather he was told he would play a bunch, per NFL Network. 

"He didn’t know for sure he was (starting) until today," Shanahan said. 

McCaffrey had been dealing with a calf/Achilles injury for the past couple