Kyle Shanahan confident Christian McCaffrey will “come back fast” from calf injury

49ers head coach Kyle Shanahan didn't have any updates on wide receiver Brandon Aiyuk or left tackle Trent Williams on Tuesday, so it remains unclear when or if either player will be back with the team. Running back Christian McCaffrey has also been out of practice, but the outlook is a bit clearer on his front. McCaffrey has been sidelined by a calf strain and he said a couple of weeks ago that he has been working with an eye on being back for the first week of the regular season. That work and McCaffrey's overall preparation leaves head coach Kyle Shanahan confident that it won't take much time for McCaffrey to be back to full speed. "He's obsessed with it," Shanahan said, via 49ersWebzone.com. "And so when you do get in these situations where you do get hurt and you can't go do all that stuff, at least he's put the work in before. So that stuff does come back fast. But he understands what it takes to play in this game, especially at the level he does. And not many people play at that level unless they are like that."The 49ers will open the season against the Jets on Monday Night Football and McCaffrey will be front and center in their attack barring any new developments in the...