SEATTLE — San Francisco 49ers running back Frank Gore was ruled out for the rest of Sunday’s game against the Seattle Seahawks after suffering a concussion in the first half.

Gore, who leads the 49ers with 804 rushing yards this season and is chasing his fourth consecutive 1,000-yard campaign, was injured while delivering an open-field block to Seattle linebacker Bobby Wagner.

Gore was downfield blocking for teammate Bruce Miller on a 10-yard pass reception and delivered a helmet-to-helmet blow to Wagner that appeared to knock Gore out briefly. He began moving after a couple of seconds and was eventually helped off the field.

Gore’s status was unknown heading into halftime, as he continued to undergo concussion tests. But early in the second half, the 49ers announced that he was out for the game.

Gore had 29 yards and the game’s first touchdown on 11 carries in leading the 49ers to a 7-3 halftime lead.