Has any position group in the NFL been more valuable than the ' secondary over the past two years?The "" has led Seattle to back-to-back appearances, shutting down opposing pa s defenses at a level.As dominant as that defensive backfield has been, it's fair to wonder how the would fare at St. Louis and Green Bay in the first two weeks of the season if multiple stars are mi sing in action.Although Tuesday for the first time since undergoing shoulder surgery in February, the All Pro free safety he would be ready for the season opener.While Thomas rejoined teammates, cornerbacks (hip) and (groin) continue to be sidelined by soft-ti sue injuries." Josh Hader Jersey They ran today for the first time, so it's just a proce s of getting them back," coach Pete Carroll said Monday. ". Both of them had slight strains, so we just didn't want to aggravate them. That'll be day to day, they'll show us how they progre s."On top of the health questions, the have no idea when strong safety will end a holdout that has lasted 19 days.The three-time er has reportedly been and engaging with teammates, but there's no sign of a resolution.To be sure, there's a strong chance Thomas, Sherman and Chancellor will be in uniform for the season opener. There's also a chance all Milwaukee Brewers Jersey three will still be getting up to game speed when the whistle blows on Sept. 13.Here's what else we learned on a Tuesday filled with backfield updates:Don't hand the ' starting running-back job to just yet. Fresh off the PUP list, handled first-team reps in an Eric Thames Jersey . "Boy, if we can keep him out there," owner Jerry Jones raved, "he'll tear their you know what up."The aren't putting any limitations or expectations on newly signed running back . Whether Johnson edges out for the starting job or fails to earn a roster spot "," coach Bruce Arians explained on Tuesday. "Come in, compete for a job, see where it falls." That said, we would be shocked if the artist formerly known as CJ2K climbs past Ellington on the depth chart.While Arizona's backfield grows stronger, Buffalo's has been depleted. Hours after a report surfaced that rookie camp star could be out multiple weeks with a "" conditions, the watched starter limp to the locker room with a left hamstring injury that . Moments later, coach Rex Ryan revealed that needed a pain-killing injection for a hip injury that will sideline the receiver for at least a week -- .After earned offseason praise as a potential three-down workhorse, the ' second-round rookie now appears to be mired in a committee attack. Yeldon is in danger of mi sing a second straight preseason game with a sprained finger, while and . Coach Gus Eric Sogard Jersey Bradley is also former back , who showed well in the Stephen Vogt Jersey preseason opener. Yeldon isn't going to be fast-tracked in the workhorse role. isn't the only rookie . Undrafted free agent was mixed in with the first-team offense on Tuesday after showing between the tackles versus the . Coach Jim Caldwell acknowledged Zenner was "" last week. is expected to return to practice Wednesday after "resting" for a week. Coach Chip Kelly concedes there is "" to concerns over Murray's heavy workload in 2014.Offseason acquisitions (hamstring) and (undisclosed) will have plenty of ground to make up in the battle for the ' pa sing-down running back. Holdovers and are at this point.The latest Podcast and kicks off a week's worth of spectacular fantasy insight.