San Francisco 49ers running back Christian McCaffrey is yet to play this season and is reportedly suffering from bilateral Achilles tendonitis — meaning he has it in both legs. On Thursday, Albert Breer provided an update on McCaffrey’s recovery. “Going back to August, when he started to feel like himself again, they ramped him up toward the opener against the Jets,” Breer said. “Ultimately, the Achilles flared up on him, so after the opener, they wound up shutting him down. CLICK HERE to go to PrizePicks and use code ON3 to receive a guaranteed $50 once you play $5 in lineups! “He just starte…