Mosley was sent home from London on Saturday and suspended by the Lions for an unspecified violation of team rules.
Detroit says in a release that Mosley engaged in detrimental conduct and is suspended for two weeks. The Lions face the Atlanta Falcons in London on Sunday, then Detroit has a weekend off. Detroit put Mosley on the reserve-suspended by club list. The team signed safety Jerome Couplin from the practice squad. The 31-year-old Mosley has played in all seven games this season for the Lions, with no starts. He has 2 1/2 sacks.