San Francisco 49ers assistant Bobby Turner has been coaching for a total of 46 years with the bulk of that time being spent working with running backs. When head coach Kyle Shanahan became the head coach of the 49ers, he brought Turner along with him from Atlanta. That meant the departure of the pretty good running backs coach the 49ers already had – Tom Rathman.

Turner's resume is impressive. He has made a career of taking running backs who were not high-round draft picks and helping them flourish in the NFL. An excellent example of that is Hall of Fame running back Terrell Davis, who the Denver Broncos selected in the sixth-round of the 1995 draft.

1995 was also the year Turner entered the NFL as a coach. He was hired in Denver by Kyle Shanahan's father, Mike, who had just become the Bronco's head coach.

Turner knows the importance of finding a running back who fits what his head coach is looking to do offensively.

"The key is having the right player," he told reporters on Tuesday. "It's like a marriage. It's got to be the perfect fit. He has all of the physical tools."

The 49ers said goodbye to running back Carlos Hyde, who signed with the Cleveland Browns, this offseason and hello to Jerick McKinnon, who was one of San Francisco's top free agent targets. Shanahan and company wanted McKinnon so badly that they were willing to enter a bidding war to ensure he landed with the 49ers.

What exactly does McKinnon bring to the 49ers offense?

"He can run the ball, he can catch the ball, he can pass block, and he can finish every play," Turner said. "When he breaks level two, level three, he has that explosive speed that can separate him from everyone else."

Then there is the toughness. When evaluating talent, the 49ers always look for players with chips on their shoulders and who display toughness in every aspect of the game. McKinnon may measure in at two inches shorter than Hyde and is listed at nearly 25 pounds lighter than his 49ers predecessor, but he possesses the one trait that Turner finds most valuable.

"The one thing for me throughout my career is I'm big on toughness, physically, with or without the football," Turner said. "That's guys playing hard. And so he showed that on tape, that he was physically not afraid of it. He loves to compete in there.

"Some people, they hate that part of it. They only want to compete and play hard when they have the ball in their hands. So he was special in that area."

Turner isn't the only person impressed with the 49ers new running back.

"Jerick, he's a talent," quarterback Jimmy Garoppolo said on Tuesday. "He does some things that you don't even know how he does them, is the best way to describe it. He's like a jitterbug back there, but he's savvy and smart at the same time, which is a great feeling as a quarterback having a guy like that."

The 49ers close out their organized team activities on Thursday and will reconvene on the practice field next Tuesday for a three-day mandatory minicamp.