Report: Niners' Willis has broken hand

San Francisco 49ers linebacker Patrick Willis suffered a hand injury in practice Wednesday and reportedly has a broken bone.

ESPN said that Willis has a slight fracture in his right hand, an injury that could keep him sidelined throughout the preseason.

Willis appeared to suffer the injury early in practice and spent most of the session on the sideline with his hand wrapped. He was scheduled to undergo tests on Thursday.

The 28-year-old All-Pro has previously played with broken bones in his hand, including the 2010 season when he was hurt in December and played two games with a cast before suffering further damage that caused him to miss the season-finale.