Branch broke his foot in Sunday's loss at New England and will miss the rest of the season. This marks the second straight year Branch was done in by an early season injury. He hurt his ankle in the second game of 2013 and missed the rest of the year.
Ross replaced Branch last year as starter after the injury but was cut at the end of training camp. Ross had 59 solo tackles and two sacks last year. Ross played one game for Miami before the Dolphins waived him earlier this week.
The Raiders play Miami in London on Sunday.
AP NFL website: www.pro32.ap.org and www.twitter.com/AP-NFL