SANTA CLARA, Calif. — San Francisco 49ers training camp got off to a slow start Thursday when top pick Solomon Thomas was unsigned and thus not available to take head coach Kyle Shanahan’s conditioning test.Maybe that wasn’t such a bad thing. One of the team’s key returning players, free safety Jimmie Ward, failed the test, straining a hamstring and landing on the physically unable to perform list even before the club’s first real workout Friday.Welcome to the 49ers, coach Shanahan.”Unfortunate for him and for us obviously,” Shanahan reported Friday after he put 88 players — not including Thomas, who agreed to terms during the workout — through their first day of team drills. “We don’t think it was a full pull or anything, but we want to be smart and safe with it. You never know with those things how long they’ll take.”Placing Ward on PUP could have no bearing on the 49ers’ season-opening roster. He remains eligible to be pulled off the PUP at any point during the preseason.Where the injury appears most costly is in the club’s new defensive alignment.Ward wore many hats his first three seasons after being the club’s first-round pick in 2014. He made 18 starts at strong safety and cornerback, and in essence started every other game when healthy as the nickel corner.With strong safety Antoine Bethea no longer around, Ward was penciled into the starting free safety position for 2017, with Eric Reid, another former first-round pick, moving to strong safety.But effective Friday, that plan must be re-evaluated.Ward’s backup is Jaquiski Tartt, who is more of a strong safety than free safety, so it’s possible Reid will be moved back to his previous position while Ward is out.Injuries have set the former Northern Illinois player back in his first three seasons. He missed 15 games with foot, quad and collarbone injuries.Thomas, meanwhile, is slated to debut Saturday.”Solomon’s a guy’s who’s in shape,” Shanahan claimed of the No. 3 overall pick in the draft out of Stanford. “(Strength and conditioning coach Ray Wright) took him through our conditioning test. We’ve seen his workouts and stuff.”ROOKIE TO WATCH-TE George Kittle was a handful for 49ers linebackers and safeties to cover on the first day of training camp. He certainly looked more elusive than productive holdovers Vance McDonald and Garrett Celek. No doubt, the fifth-round pick is in the mix to be a starter this season.