Running back Jerick McKinnon is out for the remainder of the preseason, but San Francisco 49ers general manager John Lynch said the team is hopeful their new starter is ready for Week 1 of the regular season.Lynch said McKinnon is slowed by a right knee injury, but the 49ers said the injury is not serious.Jeremy McNichols has been working with the first-team offense for the 49ers with McKinnon and Matt Breida out. Former Redskins and Cowboys running back Alfred Morris signed a one-year deal with the team this week.First injured in a practice Sunday, McKinnon’s MRI and additional tests showed no major damage, the 49ers said.McKinnon, 26, is being counted on heavily by the 49ers after signing a four-year, $30 million contract in the offseason.McKinnon spent his first four NFL seasons with the Minnesota Vikings. He rushed for a career-best 570 yards and three touchdowns last season.
