Jimmie Ward was moved from cornerback to safety during the offseason, which makes his lengthy absence this summer a bit concerning.
That is, will Ward be ready for the regular season after missing training camp and the first two preseason games with a hamstring injury?
Ward’s response: He’s done this before.
“It’s only a concern to people who don’t know I can play safety,” Ward told reporters. “To me, I feel comfortable. It’s my natural position.”
Ward was a 2014 first-round pick based on his performance as a safety at Northern Illinois. He’s spent his first three NFL seasons at cornerback, with the exception of a start at safety in 2014.
He’s now tasked with playing free safety in a 4-3 defense and his position has been labeled the “Eraser” because it’s his job to clean up others’ mistakes as the last line of defense.
Ward was activated from the physically unable to perform list Wednesday after he was injury during a conditioning test on reporting day July 27.
He’s being eased in gradually to practice this week and defensive coordinator Robert Saleh said he doesn’t know if Ward will play Sunday when the 49ers visit Minnesota. Teams typically rest their starters in the preseason finale, meaning it’s possible that Ward won’t play until the regular-season opener on Sept. 10.
Saleh said he wasn’t concerned about Ward’s understanding of his new position. However, he acknowledged his lack of contact could present a challenge. Ward hasn’t had snaps where he faces ballcarriers in the middle of the field.
“To me, the hardest part is being able to track and tackle,” Saleh said. “Coming out of the middle hole, when the defense gets creased and it’s him and the back one-on-one. That’s the hardest tackle in football in my opinion. Those are the reps that he hasn’t gotten.”
Reunited: Defensive tackle Sen’Derrick Marks, who was signed Wednesday, will fight for a roster spot at a positon that includes reserves Quinton Dial and Chris Jones.
Marks, 30, had a career-high 8.5 sacks with the Jaguars in 2014, but a torn ACL and torn triceps tendon have helped limit him to one start and 22 tackles the past two seasons. Marks spent the past three seasons with Saleh, who was Jacksonville’s linebackers coach.
“He’s had a good past,” Saleh said. “He’s a good football player. We’re just trying to work him into shape. He hasn’t been through OTAs, training camp and all that stuff. But give him a chance to play these next two games and see what he’s got.”
Injury report: Cornerback Will Redmond (ankle) and wide receiver Aaron Burbridge (hamstring) did not practice.
Fullback Kyle Juszczyk wore a non-contact jersey for the second straight day because of a shoulder injury that is not considered serious.
Eric Branch is a San Francisco Chronicle staff writer. Email: firstname.lastname@example.org Twitter: @Eric_Branch