The San Francisco 49ers have been using their depth on defense often this year as several key players have been sidelined.The latest may be powerhouse defensive lineman Ray McDonald who injured his right bicep and could miss some time. If McDonald is out, he will be replaced by Tony Jerod-Eddie. Let's a look at him because we could be seeing more of Jerod-Eddie.Vitals: 6-foot-5, 301 poundsSchool: Texas A&MHow acquired: Undrafted free agent in 2012 (with that draft class a near total bust, perhaps he can salvage it).