49ers RB Jordan Mason (shoulder) to undergo tests

(Photo credit: Darren Yamashita-Imagn Images)
San Francisco 49ers running back Jordan Mason is scheduled for tests to determine the severity of a shoulder injury that knocked him out of Thursday's win at Seattle.

Head coach Kyle Shanahan said Mason, starring as the fill-in for injured starter Christian McCaffrey with an NFL-leading 114 carries and 609 rushing yards, had X-rays on Thursday after being hurt on his eighth c