By Joseph Salvador This will be his fourth team in the last two years. View the original article to see embedded media. The Raiders announced they signed quarterback Nick Mullens on Monday. The journeyman signal-caller most recently played for the Browns. Mullens went undrafted in 2017 after four years at Southern Miss but signed with the 49ers that offseason. He never appeared in a game his rookie year, however. He was named the starter in ’18 when Jimmy Garoppolo tore his ACL in the middle of the season and started in all eight of his appearances that year. He finished with 2,277 passing yar…