two days after he was a surprise inactive in Monday night's season opener San Francisco 49ers running back Christian mcaffrey explained how the decision to sit him out was made and why he was adamant Friday he would be available to play speaking to Bay Area reporters before Wednesday afternoon's practice mcaffrey attributed his confidence he'd be able to play last week to the mentality he believes is necessary in such situations my mindset every week is I'm going to play mcaffrey said there's been weeks where I'll go the full week not even feeling good enough to do the walkthr and then I wake up and the body's capable of a lot of cool things mentally I'm always prepared to play and then I woke up and it was a group decision a very tough one I hate not playing but I look at it as a chess move and something that hopefully you can benefit from the rest of the season