Willis (concussion) participated in Tuesday's practice, Nick Wagoner of ESPN.com reports.
It's a positive sign for Willis, who entered the league's concussion protocol during the 49ers' preseason finale against the Raiders this past Thursday. Even if he fully participates in practice, he'll remain in the league's protocol until cleared by an independent neurologist. The fourth-year pro made the 49ers' 53-man roster as a depth option at tight end behind George Kittle (Achilles), Jake Tonges and Luke Farrell.