I couldn't find any information about Mike Onwenu's ankle injury in the wiki — there's no player page for him, and no recent news items covering an injury. The wiki currently covers fantasy-relevant skill position players pretty comprehensively, but Onwenu (an offensive lineman) doesn't have an entry.
That said, since Onwenu is a guard for the Patriots, his injury status would affect the New England offensive line's cohesion — which could matter for Drake Maye's protection and the run game. But for fantasy purposes, offensive linemen aren't individually tracked here, and I don't have details on the severity or timeline. You'd want to check a Patriots beat reporter or the team's official injury report for the latest on this one.