A.F.C. Championship Live Updates: After Piecing Together a Drive, Cincinnati Trails, 6-3

KANSAS CITY, Mo. — He answers to the nickname Jet, confesses to having “little man” syndrome and has a high-pitched voice — constantly imitated by his teammates and coach — that would make a high school freshman blush.

But Jerick McKinnon, the Chiefs’ diminutive running back, has also made an outsize contribution as something of a quarterback helper. He caught nine touchdown passes during the regular season to tie the Hall of Famer Marshall Faulk’s 2001 mark for scoring receptions by a running back.

At 5-foot-9 and 216 pounds, McKinnon has also been a shockingly effective blocker, a skill that may help fend off the Bengals’ defense in Sunday’s A.F.C. championship game with quarterback Patrick…