Mac Jones still limited and not throwing yet; Jauan Jennings improved to limited

49ers wide receiver Jauan Jennings (ankle/rib) returned to a limited practice. He missed Wednesday's work.Jennings played the first two games, missed Week 3 with ankle and shoulder injuries, played Week 4 and missed last Thursday's game with his ankle and rib injuries."I think it's close to the same thing as last week," coach Kyle Shanahan said Thursday on KNBR, via David Bonilla of 49erswebzone.com. "You know, having more time to do this [after a Thursday night game last week], he definitely has a better chance. He was able to do a few things today, but I think that one will come down to the wire."Quarterback Brock Purdy (toe) remained out of practice, making it even more likely that Mac Jones starts again Sunday. Jones (knee/oblique) remained limited on Thursday."Yeah, he wasn't able [to throw] today," Shanahan said of Jones, "so he just focused on handoffs and stuff like that. So, really trying to rest it up. Should be good to go on Sunday, but definitely wasn't good enough to go today. So hopefully, that'll continue to improve."Defensive tackle Alfred Collins (knee) returned...