The Colts running back suffered a right hand fracture in Sunday's 33-13 win over the Jacksonville Jaguars, NFL Network Insider Ian Rapoport reported, per a source informed of the situation. The severity of the fracture is uncertain and will be determined in a visit with specialists this week, but it's very unlikely Mack plays in Indianapolis' Thursday night game against the Houston Texans, Rapoport added.
Mack had a highlight-worthy touchdown run in the first half Sunday and finished with 109 rushing yards on just 14 carries, but took his last handoff less than four minutes into the second half. The Colts eventually scored on the same possession, but Mack did not return due to the injury.
Jonathan Williams was excellent in Mack's place, racking up 116 yards on 13 carries and catching one pass for 31 yards. It was Williams' best outing of his career, meaning it would be unfair to expect something similar out of him against Houston on a short week. But as Sunday showed, Williams is capable of filling in for Mack.