Aug. 15 7:53 AM PT8:53 AM MT9:53 AM CT10:53 AM ET14:53 GMT10:53 PM 北京时间7:53 AM MST9:53 AM EST8:53 AM CT18:53 UAE10:53 ET - Mitchell has signed with the Miami Dolphins after spending the past four seasons with the New Orleans Saints. Analysis: Mitchell joined practice Monday and wore No. 52, which was worn by Channing Crowder until his release last month. Mitchell, a former seventh-round draft pick from Tennessee, played mostly on special teams for the Saints. Last year he had 30 tackles, one sack, two fumbles forced and two fumbles recovered.