The San Francisco 49ers made a big-splash signing before free agency officially kicked off in March. The team acquired All-Pro cornerback Richard Sherman the day after the Seattle Seahawks released him.

The marriage between team and player made perfect sense. Sherman was the prototypical cornerback for a Robert Saleh defense. If you look at the group of cornerbacks on the 49ers practice field, almost all of them look the same when it comes to body type. Most of them are hovering around 6-foot-3 with similar weights and wingspans.

For the Niner Faithful, the signing of Sherman may have been a tough pill to swallow. 49ers fans had grown accustomed to despising the rash cornerback who was coming from a long-time bitter division rival. After five months of learning about Sherman, hearing what he's had to say, and watching as he mentored the younger defensive backs, feelings have changed.

Sherman didn't just get under the skin of opposing fans. He apparently frustrated opposing coaches. 49ers head coach Kyle Shahanan joined KNBR on Thursday night and spoke at great length about the new piece to his defense. He had a lot to say when it comes to how Sherman is perceived.

"I played against him a ton and wasn't a huge fan of him," Shanahan said. "I always respected him. He drove me crazy just like he's probably driven every Niners fan crazy. And you get an impression of guys when you see them on TV and stuff. I know he's been outspoken and stuff like that, so everyone has their own opinion of that, but you don't know someone until you talk to them.

"Very quickly, the first night I met Richard, going out to dinner with him, him and his wife (then ffiancé) for about four hours, you realize that there's a reason he's so successful. Yeah, that guy, he's very confident. He'll let you know, he'll say it, but it's not a show. He believes it. That's his mindset.

"He's as competitive a person as I've been around and that's his edge. He's extremely talented, but I think there's other guys that have been as talented that he has passed up each year in the league."

Sherman is entering his eighth NFL season. He has been selected to four Pro Bowls and is a three-time first-team All-Pro. Over the course of his career, no cornerback has allowed a lower passer rating (47.7) when targeted than Sherman, according to Pro Football Focus. Between 2012 and 2017, he had 94 consecutive games allowing fewer than 100 yards in coverage.

"He is competitive, he works at everything, he's not scared to fail, he'll put himself out there," Shanahan continued, "and I love for our young guys to see that because we've got some talented young guys who believe they can do it. They got some opportunities last year and had a little success towards the end. When guys have that, they say, 'Hey, I think we can play.'

"Then you get a guy like Richard, that they've seen do it consistently over time. He brings a certain mentality and mindset that I think that they feed off of and that's something our guys need."

One of those young guys is second-year safety Adrian Colbert, who also joined KNBR on Thursday. He explained what it is like having an opportunity to play alongside and learn from a savvy cornerback like Sherman.

"Just having that veteran presence, especially with the system, and him being in the system previously, is like whatever he says, you're going to listen to it," Colbert said. "Ears wide open because he knows what he's doing. He's won a Super Bowl. He's been on the best defenses in the league for years. It's great to have that type of guy in your room and just to listen to. You've got to soak it in. You've got to be a sponge when Sherm talks."

Some questioned the decision to sign a 30-year-old (29 at the time) cornerback coming off of a ruptured Achilles. Many wondered and still wonder whether or not Sherman can return to form. When video of wide receiver Marquise Goodwin, who is one of the fastest players in the league, beating Sherman during one-on-one drills made its rounds on social media, the critics were quick to overreact.

You can't always take what happens in practice and draw conclusions from it because you typically don't have the whole picture. You don't know what the offense and defense are working on or what the defenders are being asked to do. Shanahan dives further into the negatives of speculation based on practices during his interview (give it a listen), and Saleh also warned not to overreact when it comes to Sherman's performances during drills.

"I think he's been great so far," Shanahan said of Sherman.

Regarding the injury, the 49ers are still being cautious even through Sherman looks well on his way to recovery. He worked diligently with the 49ers training and medical staffs to make certain he was able to get back onto the practice field without any setbacks.

"Richard had a big injury last year, a huge rehab he had to go through," Shanahan said. "He attacked that as hard as he could. We knew our plan was to have him at training camp, but you never know. If it was at all close, we were going to be safe with him."

Sherman reported to training camp, went through his physical, and was medically cleared to fully participate in practices for the first time since his injury. Now, the 49ers are working on his stamina, recovery time from practice, and any lingering soreness, which the head coach doesn't sound too concerned about.

"When we got back here after being away for 40 days, we didn't need to go easy right away," Shanahan said. "He was ready to go, and he wanted to go, and he deserved to go. We're taking care of him. We give him two days on, one day off. I do think he's healthy."

You can listen to the entire interview with Shanahan below.