It seems the San Francisco 49ers are set to lose not one high quality inside linebacker to retirement this offseason, but two.

Only a week after perennial Pro Bowler Patrick Willis shocked the 49ers family and the NFL world by announcing that he would retire due to injury concerns, second-year 'backer and heir apparent to Willis' spot on the inside of the vaunted 49ers defense, Chris Borland, is set to do the same due to concerns over head injuries.

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

The 24-year-old Borland said that he informed the 49ers on Friday of his intentions after meeting with friends, family, concussion researchers, current and former teammates, and studying the correlation between the repetitive head trauma inherent to football and issues of depression, memory loss and brain damage.

"I feel largely the same, as sharp as I've ever been, for me it's wanting to be proactive," said Borland, the former University of Wisconsin standout. "I'm concerned that if you wait till you have symptoms, it's too late. ... There are a lot of unknowns. I can't claim that X will happen. I just want to live a long healthy life, and I don't want to have any neurological diseases or die younger than I would otherwise."

Borland was a surprise standout for the Niners last season after being selected in the third round of the 2014 NFL Draft and seeing significant time due to Willis' injury in Week Six.

He said that intial misgivings surfaced during training camp when he suffered what he believed to be a concussion while making a tackle during a run play, but stayed in and played through the issue.

"I just thought to myself, 'What am I doing? Is this how I'm going to live my adult life, banging my head, especially with what I've learned and knew about the dangers?'," he said.

Borland would finished the year with 107 tackles and a sack in just 14 games, garnering one vote for Defensive Rooke of the Year.

After consulting with concussion researchers in the offseason, Borland dubbed the decision a "simple" one.

"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," said Borland, who was adamant that Willis' retirement had not and would not affect his decision.

Borland, who said he has only had two diagnosed concussions in his life, figured to take on a leading role alongside Navorro Bowman on the inside for the Niners next season after Willis' retirement, but it now seems San Francisco will be tasked with replacing not one but two starting linebackers in a single offseason - an offseason that has already been replete with change for the formerly formidable Frisco franchise.