SANTA CLARA – A season-ending injury to a starter might not have the same negative impact when it forces a supremely talented first-round pick into the starting lineup.

But do not try to convince the 49ers’ coaching staff that it will be easy to compensate for the loss of linebacker Malcolm Smith to a season-ending torn pectoral.

“He was unbelievable -- looked like the Super Bowl MVP,” 49ers defensive coordinator Robert Saleh said of Smith, who was, in fact, the MVP of Super Bowl XLVIII while with the Seattle Seahawks.

“I don’t hurt as much for the organization as I do for him and all the hard work he put in this offseason to position himself to have the best year of his career. For that to happen to him when it happened to him, I feel sick for him.”

Rookie linebacker Reuben Foster was going to be a starter. It was just a matter of the timing. Now, there is more urgency to get the 31st overall pick ready to go for the Sept. 10 opener against the Carolina Panthers due to Smith's absence. Smith was placed on season-ending injured reserve on Monday.

“Yeah, I'm ready,” Foster said.

Well, maybe not quite, yet.

Foster has made his mark during the practice sessions with some interceptions. But he has also blown more than a few assignments. The most encouraging part for Saleh is that Foster has been able to quickly correct his mistakes.

“He’s had flash plays and he’s had busts that a common person won’t notice,” Saleh said. “But, at the same time, he’s been asked to learn a lot in a very short amount of time. So, for Reuben, it’s just a matter of getting those reps.


“What’s great about him is that when he sees it once he’s good. So, even if he’s made a mistake he’ll be able to recoup, re-gather himself back up.”

Foster lined up with the 49ers’ first-team defense on Monday. The plan is for veteran Ray-Ray Armstrong to line up at the weakside linebacker position on Tuesday.

Foster figures to be at his best when he is allowed to show all of the traits that prompted the 49ers to rank him as the No. 3 prospect in the draft behind Myles Garrett and Solomon Thomas.

Saleh was referring to his entire defensive unit, but he could have been speaking solely about Foster when asked what he was looking forward to seeing on Friday night.

“I can’t wait to see us tackle,” Saleh said. “I can’t wait to see us hit. I can’t wait to see the violence with which we play.”

Foster had to resist the temptation to put a hit on teammate Carlos Hyde on the third play of the day, as the players came face to face in the hole on a running play. The big hits will have to wait until Friday.

--Linebacker Eli Harold is nearing the final stages of completing the concussion protocol. He wore pads and went through non-contact football activity.

--Arik Armstead's deflection at the line of scrimmage of a Brian Hoyer pass led to Dontae Johnson’s interception, which he returned for a touchdown.

--Tank Carradine continues to be the first-team defensive end ahead of Solomon Thomas, the No. 3 overall pick. But Thomas appears to be gaining ground. “Solomon is starting to show up,” Saleh said.

--Nose tackle Quinton Dial recorded a sack on a stunt against No. 2 right tackle Garry Gilliam.

--Aaron Lynch returned to work after missing two practices after the premature birth of his son. He batted down passes from Matt Barkley and C.J. Beathard at the line of scrimmage.

--Cornerback Rashard Robinson left practice early with an apparent left shoulder injury.

--Coach Kyle Shanahan was not pleased with the way a backed-up period began. After four pre-snap penalties, including two false starts from Trent Brown, Shanahan stopped the action and had the team begin over.

--Running back Raheem Mostert fumbled near the sideline after a big hit from Lorenzo Jerome.

--During a 7-on-7 red zone period, tight end Vance McDonald beat Eric Reid on back-to-back touchdown passes from Hoyer of 6 and 3 yards. McDonald worked mostly with the backups in later 11-on-11 drills.