Injuries mounting before preseason opener NBC Sports Bay Area & California [Video]

SANTA CLARA — The 49ers entered their fourth block of training camp practices on Tuesday with all eyes searching for Brandon Aiyuk, who was not seen around the practice field as he has been the last few weeks.

The 49ers went about business as usual with a few players sitting out due to veteran rest days, including defensive lineman Leonard Floyd, edge rusher Nick Bosa, defensive lineman Javon Hargrave and fullback Kyle Juszczyk. 

Linebacker Demetrius Flannigan-Fowles, running back Elijah Mitchell and wide receiver Tay Martin were seen working with trainers on the side of the field along with rookie running back Isaac Guerendo, who looks like he is getting closer to returning to action.

Coach Kyle Shanahan revealed after practice that punter Mitch Wishnowsky is dealing with knee irritation that has kept him out of practice, which is why Juszczyk has been seen holding for kicker Jake Moody. 

It was a shorter team drill session, …