Jordan Mason stars as San Francisco 49ers open with MNF win - ESPN

SANTA CLARA, Calif. — For the past two-plus seasons, Jordan Mason has always looked the part of a starting running back. He just hadn't been able to play it until Monday night.

The wait might have been longer than Mason wanted and come about under less-than-ideal circumstances — replacing an injured Christian McCaffrey — but it was clear in the season opener that Mason was more than ready for the job as he and the Niners battered the New York Jets on the ground in a 32-19 victory.

«I've been working all of training camp for this moment and I'm blessed to be able to get to play today and show it,» Mason said.

By the time Mason was done, he'd set career highs with 28 carries for 147 yards. He added a rushing score and caught a pass for 5 more yards. After the win, some were left wondering when the Niners knew McCaffrey would be out and Mason would be in.

In an on-field interview with ESPN's Lisa Salters, Mason suggested that he found out «maybe Friday night» that he could be in line for the start. Coach Kyle Shanahan offered that no decision was made on Friday and nothing was decided until Monday.

Regardless, Mason's start came as a surprise after McCaffrey was announced as an inactive 90 minutes before Monday night's game because of lingering calf and Achilles injuries. During the week, McCaffrey participated in all four Niners practices on a limited basis and was officially listed as questionable on Saturday's final injury report.

Despite all of that, the expectation for McCaffrey was that he would be ready to roll. McCaffrey said Friday afternoon he had no doubts that he would play against the Jets and expressed hope he'd be in line for his usual heavy workload.

After the game, Shanahan said that «it was a little too