Week 1 got off to a shocking start for the San Francisco 49ers.

Star running back Christian McCaffrey was pulled from the game against the New York Jets at the last minute. His calf/Achilles injury, which had been bothering him for the past month, was too much to overcome. It was shocking to see, as he was so adamant about wanting to play.

“Exactly the same stuff that’s been bothering him all week,” Kyle Shanahan said of McCaffrey’s inactivity. “Today it was a little too much, a decision made just before the game. He came in, I just talked to him about it, but it was still there. I thought it was smart to leave him out and I’m glad we did.”

It was certainly a smart decision not to play McCaffrey. An Achilles injury is no fun, no matter how minor. Benching McCaffrey isn’t a problem when the 49ers have a great backup like Jordan Mason. And boy was he phenomenal against the Jets, rushing 28 times for 147 yards and a touchdown.

The 49ers should rest McCaffrey in Week 2 against the Minnesota Vikings. Playing it safe is the best course of action with McCaffrey. When he was inactive against the Jets, it suggested his injury was worse than admitted.

McCaffrey is an extremely tough player. Had his injury not been so severe, he would have played. But the fact that he was unable to play shows that he is dealing with a serious injury. And it’s not like his calf/achilles injury is going to get significantly better in less than a week.

Giving him a rest against the Vikings, an average opponent at best, is smart. The 49ers offense hasn’t missed much with Mason as the starter. Mason has proven that the offense can maintain a high level with him as the starter. His performance against the Jets should make it easy for the 49ers to determine McCaffrey’s status.

Shanahan, however, sees things differently.

“Not really. We always think very highly of JP. When he’s been in those situations, he’s always done that,” Shanahan said. “You always want Christian out there. What he brings to the running game, what he brings to the passing game. It’s great to have Christian. But at the cost of losing him for more games.”

It makes sense that Shanahan wants his best offensive player back. If he’s healthy enough and ready, the 49ers will let him play. But why take that risk if it’s unnecessary? They don’t necessarily need him back. The 49ers have a good running back in Mason who will keep them dominating.

Taking McCaffrey out for another week to rest isn’t as damaging as letting him play. The 49ers have the whole season to think about here. His calf/Achilles problem has been around since late last year. Take it slow or risk being without him for a longer period of time.

The decision here is simple. Bench him against the Vikings and let Mason continue to flourish. His place will be there once he’s fully healthy again.