49ers RB Christian McCaffrey reportedly a long shot to play vs. Vikings

Christian McCaffrey's Achilles injury seems likely to sideline him for a second straight game.

The San Francisco 49ers star running back is considered a long shot to play in Sunday's game against the Minnesota Vikings, NFL Media reported Wednesday. 

McCaffrey has been dealing with a calf injury since the early days of training camp in August. The 49ers sidelined him through the rest of camp and the preseason, but it was expected that he would play in Week 1 against the New York Jets. However, McCaffrey was scratched from the lineup 90 minutes prior to their win against the Jets on Monday.

Even though the 49ers listed McCaffrey as questionable with an Achilles/calf injury in the days prior to the opener, the news of his scratch was a bit of a surprise. 49ers coach Kyle Shanahan shared that McCaffrey's Achilles issue was tendinitis with the muscle, as he downplayed any long-term concern on Tuesday

"The Achilles is tendinitis and that stuff comes and goes," Shanahan told reporters. "When it is acting up, it's something you've got to be very careful about. Christian's very diligent about that stuff. If it was a playoff game, he made it very clear to me he believed he could go. But when you hear that type of stuff and it's not a playoff game and it's Week 1, especially when you're dealing with the lower extremities like that, it was a tough decision. But hearing all the words in the long run, it made it easy."

Shanahan also told reporters that McCaffrey was "day-to-day" with the injury. 

If McCaffrey can't go against the Vikings, the 49ers know that their running game could be effective without the reigning Offensive Player of the Year. Third-year running back Jordan Mason had a career night versus the Jets, rushing for 147