49ers secondary coach Tim Lewis turned injury into career

Recommended Video:

Tim Lewis’ post-playing career began 29 years ago at the Mayo Clinic in Rochester, Minn.

A surgeon showed him X-rays of two spines: One was normal. The other belonged to Lewis.

The doctor was blunt: The Packers’ cornerback, the No. 11 overall pick in 1983 who had 16 interceptions in three-plus seasons, had to retire at age 24.

“He had me look at the X-rays,” Lewis said, “and he told me: ‘Here is what’s normal. Here’s what you’ve got. You can’t play again. You never should have played. You’ve been lucky to this point. It’s time to move on.’”

Lewis moved on, but the 49ers’ secondary coach did not put his economics degree from Pittsburgh to much use after he was diagnosed with spinal stenosis, a narrowing of the spinal cord.

This week, Lewis, 53, reflected on a coaching career that began shortly after he was left motionless on the grass at Lambeau Field following a collision with Chicago wide receiver Willie Gault. Despite the sudden end to a promising career, Lewis’ story isn’t stuffed with “what-if” regret.

Rather, he feels fortunate. Before that Monday night game, Lewis had experienced other close calls. On three other occasions, the first in high school, he momentarily lost all feeling in his arms and legs after making a tackle.

His perspective nearly three decades ago: He was out of football, but he wasn’t in a wheelchair.

San Francisco 49ers cornerback Kenneth Acker (20) intercepts a pass intended for Denver Broncos wide receiver Demaryius Thomas (88) during the first half of an NFL preseason football game, Saturday, Aug. 29, 2015, in Denver. (AP Photo/Jack Dempsey) less San Francisco 49ers cornerback Kenneth Acker (20) intercepts a pass intended for Denver Broncos wide receiver Demaryius Thomas (88) during the first half of an NFL preseason football game, Saturday, Aug. 29, ... more Photo: Jack Dempsey, Associated Press Photo: Jack Dempsey, Associated Press Image 1 of / 1 Caption Close 49ers secondary coach Tim Lewis turned injury into career 1 / 1 Back to Gallery

“It scared me half to death,” Lewis said. “Once the doctor told me it was over, I was OK with it thereafter. It was just that quick.”

Lewis was able to avoid looking back partly because he became consumed with coaching. Months after he retired, he was a 25-year-old graduate assistant at Texas A&M. After eight years in college, he since has spent 21 seasons in the NFL, a journey that has included defensive-coordinator stints with the Steelers (2000-03) and Giants (2004-06).

This season, his first with the 49ers, Lewis’ coaching acumen has been tested. Of the eight defensive backs on the 49ers’ current 53-man roster, only one — 23-year-old safety Eric Reid — began the season with more than nine career starts. The average age of the group: 24 years, 1 month.

What’s it like coaching so many kids? Lewis joked that it’s a bit easier to instruct Canton-bound legends such as former Pittsburgh safety Rod Woodson.

“I’ve had my share of coaching young and inexperienced guys,” Lewis said,“and I’ve had my opportunity to work with Hall of Famers that you didn’t have to say very much to. I’d much rather have the Hall of Famers, but the young guys are good because they’re impressionable. They know I’ve had some success, so the credibility is there.

“And then you have to keep the credibility by helping them get better.”

The secondary has improved after a forgettable opening stretch. The 49ers rank 29th in the NFL in passing yards allowed per game (280.6), but they’ve averaged 229.3 yards in their past three games.

Under Lewis’ tutelage, cornerback Kenneth Acker, a 2014 sixth-round pick who played his first NFL snap this season, ranks ninth in the NFL in interceptions (three). In addition, rookie safety Jaquiski Tartt, who has replaced Antoine Bethea (injured reserve), has made a smooth transition from Samford.

The secondary’s most impressive performance came when it was severely shorthanded in a 17-16 win over Atlanta on Nov. 8. The 49ers played without Acker (concussion), fellow starter Tramaine Brock (shin) and backup Keith Reaser (ankle).

As a result, Marcus Cromartie, promoted from the practice squad a day before the game, made his first NFL start; Dontae Johnson made his fourth career start and Chris Davis played 17 snaps despite needing a name tag.

Davis had been signed to the practice squad five days earlier and was promoted to the 53-man roster 24 hours before kickoff. In the second quarter, Cromartie momentarily left the field because of a busted lip that required stitches. In response, Lewis called on the just-arrived Davis to get in the game.

“I’m like ‘Charles! Charles! Charles! Get out there! Charles!’” Lewis said. “He’s sitting there looking at me like: ‘My name’s Chris, Coach.’ I said, ‘OK, get out there!’”

That was perhaps the only miscommunication. The undermanned 49ers limited an offense headlined by quarterback Matt Ryan and wide receiver Julio Jones to one touchdown.

Johnson, who played a starring role by breaking up a would-be, go-ahead pass to Jones in the end zone, said Lewis’ playing background has been beneficial.

“It’s always great for me to have a coach that’s played the position, to have (him) be able to draw on (his) experience and relate it to the players,” Johnson said.

As an ultra-confident young coach, Lewis thought his playing experience was enough. Like many gifted ex-players, he didn’t grasp that some players needed to be taught what had come to him instinctively. At SMU, where he was the defensive backs coach from 1989 through ’92, his players once met with him to complain about his unrealistic expectations.

“I didn’t know anything about coaching,” Lewis said. “I was able to show them, but I wasn’t able to articulate anything. I was like, ‘Just do this.’ I had to go to a number of coaching clinics. I learned very early that just because you could do it, didn’t mean you could teach it.”

Lewis has relished the opportunity to teach after his ability to play was ripped away 29 years ago. But what if he’d had a long NFL career? Would he still have become a coach?

Lewis smiled: “Yes,” he said, “because the money we were making back then wasn’t nearly as good as it is today.”

Eric Branch is a San Francisco Chronicle staff writer. E-mail: ebranch@sfchronicle.com Twitter: @Eric_Branch

Condition ends basketball career

New Mexico forward Devon Williams’ basketball career is over after doctors discovered he has spinal stenosis, the same condition suffered by 49ers defensive backs coach Tim Lewis.

Williams lost all feeling in his extremities after a fall in a game Sunday. He regained normal function 10 minutes later, but on Wednesday was given the career-ending diagnosis.

Associated Press