On Wednesday, head coach Jim Tomsula said Staley and left guard Alex Boone (shoulder, ankle) would return to practice today after missing that day’s session. Staley didn’t miss a snap in Sunday’s 17-3 loss to the Packers, but he was briefly facedown on the sideline in the first half while a trainer stretched his left leg. Kaepernick ranks 32nd in the NFL in passer rating (67.7), partly because of the 49ers are on pace to allow a franchise-record 56 sacks. Another former Pro Bowler, outside linebacker Ahmad Brooks, won’t play Sunday after his sister recently died of lupus, his agent, Greg Williams, told The Chronicle. In other injury news, four players besides Boone were limited in practice: TE Vernon Davis (knee), S L.J.