What does Khalil Herbert’s success mean for David Montgomery?

Ashlee Rezin/Sun-Times, Ashlee Rezin/Sun-Times

Chicago Bears running back Khalil Herbert runs with the ball during the second quarter against the Houston Texans at Soldier Field.on Sept. 25. | Ashlee Rezin/Sun-TimesKhalil Herbert usually has trouble sleeping after games. Thursday night, though, was particularly eye-opening.

Around 3 a.m., the Bears running back popped out of bed and picked up his iPad. He wanted to watch the play again and again and again: on fourth-and-inches early in the second quarter, Herbert was stuffed at the goal line.

There wasn’t a hole that he missed when he plowed into the Commanders’ defensive line. Herbert did think about leaping over the pile, a la Walter Payton,…