Chris Borland returning most of signing bonus to 49ers

Chris Borland, who shocked the football world recently when he announced that he was walking away from football at the age of 24, is returning most of his signing bonus to the San Francisco 49ers.

The 2014 third-round draft pick told CBS's "Face the Nation" on Sunday morning that three-quarters of his $617,436 signing bonus - or $463,077 - will be returned to his former team. 

As Matt Maiocco of CSNBayArea.com notes, the 49ers had a right to reclaim the money under the NFL's collective bargaining agreement.

Borland appeared in 14 games for the 49ers last season, recording a team-high 107 tackles, two interceptions and a sack. He cited the long-term effects of repetitive head trauma as the reason behind his decision to retire from the NFL after just one season.

Borland said he plans to return to school and pursue a career in academics or business.