CSN Bay Area

The 49ers on Monday night announced linebacker Chris Borland will retire from the NFL after just one season.

“While unexpected, we certainly respect Chris’ decision,” 49ers general manager Trent Baalke said in a statement. “From speaking with Chris, it was evident that he had put a great deal of thought into this decision. He was a consummate professional from day one and a very well respected member of our team and community.

“Chris is a determined young man that overcame long odds in his journey to the NFL and we are confident he will use the same approach to become very successful in his future endeavors. We will always consider him a 49er and wish him all the best.”

[RELATED: Borland, 24, informs 49ers he's retiring]

Borland, 24, told “Outside the Lines” he decided to retire due to the long-term effects of repetitive head injuries. Although Borland has been diagnosed with just two concussions in his life – in eighth grade playing soccer and as a sophomore in high school playing football – he made the decision after careful consideration.

He decided to retire after speaking with family members, concussion researchers, friends and current and former teammates, according to the report from Mark Fainaru-Wada and Steve Fainaru. Borland said he also studied what is known about the relationship between football and neurodegenerative disease.

Borland was involved in 128 tackles on defense and another nine stops on special teams as a rookie after the 49ers selected him as a third-round draft pick from Wisconsin. He led the team in tackles despite starting just eight games in place of Patrick Willis, who opted for season-ending toe surgery during the season. Willis announced his retirement last week.

Borland was selected to the Pro Football Writers’ All-Rookie first time. He was named NFL Defensive Rookie of the Month for November and NFC Defensive Player of the Week after recording two interceptions of New York Giants quarterback Eli Manning.