Arenado, 23, came into Friday's game hitting .302/.330/.481 (109 OPS+) with six home runs. He had a franchise record 28-game hitting streak earlier this year. Arenado is also a standout defender at the hot corner, winning the Gold Glove last year.
The Rockies did not announce any sort of timetable for Arenado's return, but it seems likely he will miss weeks, not days. A trip to the disabled list is a certainty.