Offensive lineman Justin School was injured late in the season in training this week and the 49ers removed him from the line-up on Friday.
Skule exempted from 49ers due to injury The team have also officially announced the signing of veteran attacking lineman Senio Kelemete.
He will return the injured reserve if he is not exempt.
Skule tore his ACL in training the same Monday that saw Tarvarius Moore safe go down with the 49ers torn Achilles calling for the end of the off-season workout the next day. He has appeared in 31 games over the past two seasons and has made 12 starts.
Kelemete has experience in defense and tackle and will try to use it to win a place on the list of 53 men with the Niners.