A third-round pick in 2014, McKinnon spent the first four years of his career in Minnesota. McKinnon stepped up when Vikings rookie Dalvin Cook tore his ACL in October and put together his best performance to date.
He piled up 570 yards, 421 receiving yards and five total touchdowns. He also returned 12 kickoffs for 312 yards, an average of 26 yards per return.
McKinnon signed a four-year, $30 million deal with the 49ers this offseason.
Given the team has a long-term investment in the 26-year-old running back, it is taking a cautious approach with his injury. He has put together enough film to prove he can move the football in a variety of ways and doesn't have to prove himself by playing in meaningless preseason games.
In the meantime, San Francisco can get a look at the rest of its backfield options in the post-Carlos Hyde era. Second-year running back Matt Breida is listed as McKinnon's backup on the team's depth chart, with Raheem Mostert, Joe Williams and Jeremy McNichols also among the players fighting for roster spots.
The 49ers have just more than three weeks before the regular season kicks off, and they'll want McKinnon as healthy as possible as they prepare for a 16-game grind.