Missouri quarterback Brady Cook left Saturday’s game against Auburn in the first quarter with an ankle injury.Cook came up limping on the first series for No. 19 Missouri after his leg came out from under him on a non-contact play. He jogged off the field with a trainer.The third-year starter, who is a St. Louis-area native, was replaced by veteran quarterback Drew Pyne, who previously played at Notre Dame and Arizona State.ESPN reported in the second quarter that Cook was still being evaluated, with an update expected at the half.Cook completed 3 of 4 pass attempts for 37 yards before he departed with just under 12 minutes left in the first quarter.In an interview on Sports Radio 810WHB earlier this week, Cook said he had been “a little dinged up, lower-body wise” but was feeling good and “ready to make some plays this weekend.”