Injury elevates Matt Brieda, Alfred Morris into 49ers’ backfield spotlight

SANTA CLARA - Fifteen minutes into Monday’s practice, Jerick McKinnon walked with crutches to a sideline, sat in a trainer’s cart and watched the 49ers move on without him.

Directly in his line of sight, no more than 25 yards in front of him, were his replacements, running backs Alfred Morris and Matt Breida. McKinnon stared as they took handoffs and caught passes and rehearsed the job he used to have.

“I think they will work really well together,” McKinnon said after practice at his locker while leaning on his crutches. “They’re two different backs and they both have a lot of upside. Coach Shanahan and the rest of the coaches, they do a great job of putting us in positions to be successful. That’s going to continue to happen.”

McKinnon smiled and seemed upbeat merely two days after suffering a season-ending ACL tear in his right knee. His replacements still seemed bothered by his injury.

“I almost teared up when it happened,” Breida said. “I knew something was up, because Jet gets up. He doesn’t just go down after something small.”

“Jet” is McKinnon’s nickname. He injured himself Saturday during practice making a routine cut on the final play.

“It wasn’t nothing special,” Morris said. “It wasn’t like he did anything extra. He planted. No contact. And he pulls up and falls on the ground. I went, ‘Hold on, what just happened?’ I was hoping at worst it would be just his calf, hoping he tweaked it.”

On Aug. 12, McKinnon strained his upper right calf near the back of his knee. Is it possible that calf injury led to this ACL tear? “I don’t know,” McKinnon said. “Maybe, maybe not.”

When he tore his ACL, McKinnon said he made a cut and felt his foot get stuck in the grass and his knee twist. And he didn’t just tear his ACL. “It was other stuff. I think you have to talk to the training staff about that.”

McKinnon didn’t want to talk specifics about his injury. He was more interested talking specifics about Morris and Breida, and giving his scouting report on each running back.

“Matt is obviously faster than Alfred,” McKinnon said. “But Alfred has been in this scheme before. Alfred has been in the Pro Bowl in this scheme. When I see him run, I can see why he’s so successful, because he makes a lot of the right cuts and smart moves and puts the ball where it needs to be placed. I think he’s going to help Matt come along.”

Morris went to the Pro Bowl in 2013 when he played for 49ers head coach Kyle Shanahan, who was the offensive coordinator for the Washington Redskins. Morris also went to the Pro Bowl in 2014, the season after Shanahan left Washington.

Now, Morris is 29, hasn’t rushed for 1,000 yards since 2014 and has started only five games the past two seasons with the Dallas Cowboys.

“He’s not selfish,” Breida said of Morris. “He’s not worried about, ‘I’m trying to get my money, I’m trying to start.’ He’s trying to help everybody.”

In return, Breida helps Morris learn the playbook. Morris signed only three weeks ago.

“Breida is sharp,” Morris said. “When I have questions about this offense, him and Kyle Juszczyk are the two guys I ask. He’s definitely a change-of-pace type of guy, but I think he could carry the load if he had to. It would be a different role for him, but I think mentally he has the capacity to be able to do that.”

Breida is a small running back - 200 pounds. He was the 49ers’ change-of-pace back last season behind starter Carlos Hyde, and never ran more than 12 times in a game.

Breida separated his shoulder making a block on Sept. 9 in an exhibition game, and missed the rest of the preseason. Is he big or durable enough to start?

Morris is big and durable - 224 pounds - but he may not be mentally ready to start Week 1. Although he knows Shanahan’s scheme in general, he hasn’t learned the entire offense which has evolved since he and Shanahan last worked together.

“It’s not second nature yet, and that bothers me,” Morris said. “When you think, you’re not playing as fast. Right now, I’m still learning and getting that confidence. But, I think I’ll get to a place where I can carry a heavy load.”

Neither Morris nor Breida knows who will start at running back Sunday against the Minnesota Vikings. On Monday, Breida took the first practice rep with the starters, and Morris took the second rep.

McKinnon observed and took note.