Jordan Mason stars as San Francisco 49ers open with M andf win San Francisco 49ers running back Jordan Mason did nearly everything right for his team in Monday's 32-19 win over the New York Jets in the season opener Mason a formerly undrafted player out of Georgia Tech rushed for 147 yards and one touchdown to dominate the running game after Christian mcaffrey was ruled out of week one hours before kickoff for all of Mason's rushing heroics though he may have accidentally slipped up in a postgame interview with ESPN's Lisa alters when he admitted he knew he would be the 49ers starting running back as early as Friday Mason was asked about San Francisco's running back timeline again in Monday's postgame pressor and he sounded much more irritated about having to answer the question that question right there is why I'm mad Mason said that's why I don't like really talking to Media cuz you say one thing wrong and then I no no just skip that question in the face of a potential fine from the NFL 49ers coach Kyle Shanahan clarified with reporters that he never told Mason he was going to start on Friday I told him he had to be ready a bunch but that might have been Robert Turner Jr or somebody trying to pump him up Shanahan said I knew he was going to have to play a lot told him that it wasn't going to be like usual he was going to be a number two back that was splitting a lot of the time but he didn't know for sure he was doing that until today had the 49ers known they wouldn't play mcaffrey who's recovering from calf and achilles injuries ahead of time they would have needed to report that before game day to avoid any potential fines Mason clearly regretted his comments from earlier and will probably think twice before answering lineup related questions in the future