Junfu Han / USA TODAY NETWORK via Imagn Images The Detroit Lions have downgraded rookie CB Terrion Arnold to OUT for their Week 12 game vs. Colts On Saturday, the Detroit Lions announced that they have downgraded rookie corner Terrion Arnold (groin) to OUT for their Week 12 game against the Indianapolis Colts. Arnold suffered a groin injury during Thursday’s practice, and despite getting in a full practice on Friday, he was listed as questionable, and the team was optimistic he would be cleared. “Yeah he should be good,” Lions coach Dan Campbell said of Arnold on Friday. “This morning he went in, got treatment, everything looked like it’s pretty good, so we’ll see what he looks like at practice today. I’m not concerned right now, but we’ll see how this day goes.” Unfortunately, it appears he didn’t make enough progress with his rehabilitation, and with the Lions having three games in the next 12 days—with the next two games being against NFC North rivals—coaches likely opted to play it safe and allow him to stay at home this weekend and improve his recovery status. With fellow rookie corner Ennis Rakestraw also ruled out due to a hamstring injury, the Lions will likely turn to veteran Kindle Vildor to take Arnold’s place in the starting lineup. However, there is a chance that the Lions will activate Emmanuel Moseley (pec) from injured reserve, and he could also factor into the equation. Moseley was competing for the starting nickel spot during training camp, but he has a history of starting at outside corner over his career.