49ers DE Jackson taken off field via ambulance

SANTA CLARA, Calif. -- Roughly 68 minutes into Sunday's practice session, the San Francisco 49ers' workout came to an abrupt halt as defensive end Tarron Jackson went to the ground and didn't get back up.

In what appeared to be a standard running play, Jackson was being blocked by offensive tackle Isaac Alarcon when he went down. Teammates quickly shouted for the training staff as Jackson was briefly motionless before moving his hands. His teammates dropped to a knee, and the team and sideline went silent for the next six minutes as a cart brought out a stretcher for Jackson. He was taken off the field roughly seven minutes after the injury, and an ambulance took him to Stanford Hospital about 21 minutes after he first went down.

According to coach Kyle Shanahan, Jackson was talking and moving his extremities soon after, giving hope that he had avoided any sort of serious injury.

"[You're] always scared when someone gets taken off on a stretcher," Shanahan said. "He's conscious, communicating with us, can feel all his extremities and they're taking him down to Stanford now to start further testing. So, hopefully we cleared the real scary stuff."

The 49ers originally signed Jackson, a fourth-year pro out of Coastal Carolina, to their practice squad in early January. They then signed him to a futures contract after the season. Jackson spent his first three seasons with the Philadelphia Eagles before splitting last year between the Eagles, Carolina Panthers and 49ers.

Through the first four practices, Jackson had been working mostly with the third string defensive line. After he was taken off the field Sunday, Shanahan asked his shaken-up team if it wanted to finish practice.

"We were close to him so we could hear him talking and we could see everything moving," Shanahan said. "I just told the guys that, which eases them up a little bit with the biggest fears and asked them if they were okay to continue to go. They all yelled yes and we finished the last period."

That, of course, didn't mean Jackson was far from their minds. Running back Christian McCaffrey, who was not practicing because of a scheduled day off, said such incidents are tough to handle.

"It's never good," McCaffrey said. "You've just got to pray for the best in situations like that. It's definitely a reminder not to take any day for granted. You're in a non-padded practice and you get carted off. It's a serious sport and just pray for the best for him."

Cornerback Deommodore Lenoir said it's hard not to allow your mind to wander when you play the same sport as the player being taken away on a stretcher.

"It's kind of hard because we all play in the same [sport]," Lenoir said. "When you see your brother down you kind of put yourself there. We [are] praying for him and we hope everything is going to be all right and that he gets back to us safe and sound."