49ers’ defensive lineman Tarron Jackson hospitalized during camp

That was the good news, and the 49ers will hope for more of it as the 27-year-old Jackson, who signed with the team back in January after spending time with the Philadelphia Eagles and Carolina Panthers, recovers at the hospital.

“Hopefully, we cleared the real scary stuff,” Shanahan said. “And hopefully we’ll get some good news on his neck.”

This is the first time a player has been removed from 49ers camp on a backboard since 2017, when rookie linebacker Donavin Newsom suffered a frightening concussion — but suffered no spinal damage — during Shanahan’s first season at the helm.

“It’s definitely a reminder not to take any day for granted,” 49ers running back Christian McCaffrey said after practice. “You’re in a non-padded practice and a guy gets carted off. It’s a serious sport. Just pray for the best for him.”

Shanahan called practice after Newsom was carted off on that August day in 2017. Today, the session — which was already nearing its completion — continued for a few more minutes. Shanahan told players that Jackson was moving and talking.

“I think [that] eased them up a little bit from the biggest fears,” Shanahan said. “I asked them if they were OK to continue to go. They all yelled ‘yes.’”

This was the last of four non-padded practices to begin training camp. On Monday, the 49ers will don pads for the first time this season, an important milestone in their preparation. It’ll be much easier to evaluate all positions, especially both lines, once players have their full protective gear on.

The health of the 49ers’ receiver room should be closely scrutinized as these more intense sessions begin. Shanahan is particularly demanding of his wideouts in the run-blocking game, which will grow into a featured part of practice.

Jauan Jennings, the team’s best run blocker at the position, left Sunday’s practice early with a calf issue. But the 49ers did have enough bodies to comfortably finish the session thanks to the fact that receiver Ricky Pearsall, as expected, returned to practice from the physically unable to perform (PUP) list.