Hakeem Nicks is visiting the San Francisco 49ers this week.

Nicks hasn't received any interest in the free agency market to date after catching 38 balls for 405 yards last season with the Indianapolis Colts.

Nicks has battled with injuries and drops since his 2011 season.

Colin Kaepernick is working on improving his touch with Kurt Warner and by playing flag football.

"We had some guys come out from the office playing in my corporate charity event, and there were a couple of times where I went, 'Whoa! Was that a little bit of touch I just saw?" Warner said of Kaepernick's performance this week while speaking at a Super Bowl 50 promotional appearance during the NFL Annual Meeting, per USA Today. "Colin laughed and told me, 'We're not out here working for nothing.'

"The situation forced him to throw with a little more touch. He couldn't throw it as hard as maybe he wanted to with those corporate guys.

"So we've seen strides being made. ... He's growing and wants to get better."

Warner has worked on engaging Kaepernick's lower half to help him add touch. Kaepernick is also working on improving his footwork to help get through a progression quicker.

"Is 10 weeks enough time for you to change what you've been doing your entire career? And what does that look like when bullets are flying and people are attacking you?" Warner asked. "Have we gone far enough where that becomes the norm for Colin?

"That's the big question none of us can answer. ... You talk about a guy who has been playing the position one way for 20-something years, and we're (trying) to change him in three months?"

The Chicago Bears have agreed to sign Ray McDonald.

McDonald will reunite with Vic Fangio.

McDonald was cut by the San Francisco 49ers in December after several legal issues.

Michael Crabtree is willing to remain patient to find the right deal.

Crabtree has found the free agent market soft in the offseason with the Miami Dolphins showing the most interest.

The San Francisco 49ers remain interested in re-signing Crabtree, but he would not likely get the targets or money he is seeking.

Chris Borland plans on giving back part of his signing bonus to the San Francisco 49ers.

"Absolutely not. To play one year, it's not a cash grab as I've been accused of. I'm paying back three-fourths of my signing bonus. I'm only taking the money I've earned," he said.

"This to me is just about health and nothing else. I've never played the game for money or attention. I love football. I've had a blast and I don't regret the last 10 years of my life at all. I'd do it over the exact same way. From here on I'm looking forward."

Borland had a four-year contract that included a signing bonus of $617,436. Three-quarters of that bonus would be $463,077 and Borland paying it back would give the 49ers a bit of a bump in their salary cap space.

Per ESPN Stats & Info, the 49ers had just under $14.82 million in salary cap space.

Chris Borland has decided to retire due to concerns about the long-term effects of repetitive head trauma.

Borland notified the San Francisco 49ers of his decision on Friday.

Borland made his decision after consulting with family members, concussion researchers, friends and current and former teammates, and studying what is known about the relationship between football and neurodegenerative disease.

"I just honestly want to do what's best for my health," Borland told "Outside the Lines." "From what I've researched and what I've experienced, I don't think it's worth the risk."

More than 70 former players have been diagnosed with progressive neurological disease following their deaths, and numerous studies have shown a connection between the repetitive head trauma associated with football, brain damage and issues such as depression and memory loss.

Borland is the most prominent player to retire at the start of his career due to head trauma concerns.

Borland was expected to be a key part of the 49ers defense this season after the retirement last week of All-Pro linebacker Patrick Willis. Borland replaced Willis, 30, after six games last season; Willis had sustained a toe injury.

Borland received one vote for NFL Defensive Rookie of the Year.

"I've thought about what I could accomplish in football, but for me personally, when you read about Mike Webster and Dave Duerson and Ray Easterling, you read all these stories and to be the type of player I want to be in football, I think I'd have to take on some risks that as a person I don't want to take on." Borland was referring to former NFL greats who were diagnosed with a devastating brain disease, Chronic Traumatic Encephalopathy, or CTE, after their deaths. Duerson and Easterling committed suicide.

The San Francisco 49ers have signed Reggie Bush.

Bush will join a 49ers' backfield that includes Carlos Hyde and Kendall Hunter as they move on without Frank Gore.

Bush was released by the Detroit Lions released on Feb. 25 after he played in 11 games due to a lingering ankle issue. 

Frank Gore has signed with the Indianapolis Colts.

Gore will receive $8.5 million in guaranteed money.

Gore has spent his entire career with the San Francisco 49ers.

Gore previously was believed to have a deal done with the Philadelphia Eagles.

The San Francisco 49ers have agreed to sign Torrey Smith to a five-year, $40 million deal.

Smith will receive $22 million in guaranteed money.

Smith has been one of the NFL's best deep threats at wide receiver and will team with Colin Kaepernick.

Bruce Miller has been cited in Santa Clara on a spousal battery charge.

Miller is a fullback on the San Francisco 49ers.

The 49ers also had a domestic incident investigated over the past year involving Ray McDonald.