San Francisco 49ers cornerback Richard Sherman is now two offseasons removed from the Achilles injury he sustained in 2017, the effects of which lasted throughout most of the 2018 season. He didn't start feeling more like himself until last November. Having the sutures removed in late-February helped, too.

Looking at that timeline, Sherman started feeling much-improved about a year after the injury occurred.

Cornerback Jason Verrett is a year removed from a similar injury. Although, he told reporters this past week that he didn't have any sutures put in place. The 49ers have been easing him back into practices during training camp as Verrett ramps up his work to compete with Ahkello Witherspoon for that starting job across from Sherman.

Head coach Kyle Shanahan joined KNBR on Thursday and discussed Verrett and Sherman, both of whom he hopes make significant impacts during the upcoming season.

"It's a mental thing (for Verrett) right now," Shanahan told Mark Willard and Tom Tolbert. "He hasn't played football for almost two years. He's gotten back out there. He's gone every day. But his reps are shorter than the other guys. We get him in and out. We're easing him in, and we'll build this up as we go."

The 49ers didn't do much this offseason to upgrade the defensive backs. Verrett was brought in on a one-year prove-it deal worth up to $3.6 million. There are injury concerns, after all, so the signing is a bit of a gamble. It is, however, a gamble that has the potential to pay off big.

Verrett has been injured during four of his five NFL seasons. That one healthier season resulted in a Pro Bowl selection for the talented defensive back.

"We wanted to get better in a number of areas," Shanahan continued. "You've got a choice. You can either go get some high-priced corners and safeties, or you can go get some pass rushers, and we wanted to get the outside edge rushers.

"We also feel we can win with the guys that we have. Getting a guy like Jason Verrett, his upside is huge. He has that ability, and to get him here in this situation is great for us. I think he will be healthy here. He's put in all the work, and I'm really pulling for him."

Defensive coordinator Robert Saleh discussed Verrett after Saturday's practice.

"Verrett, he looks really sharp," Saleh told reporters. "He had a really nice play yesterday, showed great patience on Marquise Goodwin, which is very hard to do when he's screaming up the field. His foot quickness and speed and all that is right there, so I like the progress he's going into or he's showing.

"He just needs to continue to get better. He'll get more of a load as we go and keep gaining confidence that he's healthy and that he's going to make it through this year, 16 games. That's the mindset."

Then there is Sherman who is feeling healthier than ever and could be back to his All-Pro form.

"Sherm is night and day compared to last year," Shanahan said. "He did do some good things last year, but guys avoided him. They didn't go after him. To see him come back this year, he's so much healthier. Last year, he battled through a lot of stuff, wasn't able to really work out all offseason because he was just rehabbing his Achilles.

"This year, he was healthy the entire offseason, was able to run, lift his legs, work, and you can see a total difference right now in training camp with just how he's moving."

As Shanahan noted, the 49ers' improved pass rush will help the defensive backs this season. That unit hauled in an NFL-record low two interceptions last year. The team went out this offseason and added veteran Dee Ford and rookie Nick Bosa to set the tone of the defense along the edges.

"People in this league rarely get interceptions just because they're locking people down," Shanahan added. "If you're locking people down, usually, the quarterback doesn't throw it. You get picks in this league because balls sail over people's heads, there's tips, the quarterback starts seeing ghosts because he's watching the D-line instead of reading coverages.

"By giving them some better edge rushers, [along with the] talent that we've had with our inside rushers, to me, that will be a huge difference for us."

You can listen to the entire conversation with Shanahan below.